Version: 2021.3
USS custom properties (variables)
Write style sheets

Built-in Unity variables

Unity’s built-in style sheets define USS variables that specify default values for Editor and runtime UI(User Interface) Allows a user to interact with your application. Unity currently supports three UI systems. More info
See in Glossary
. You can use these variables in your own style sheets to ensure that your custom interfaces match Unity style.

For information about specific variables, see the List of built-in Unity variables.

Unity variable names

Unity uses a specific naming convention for built-in variables to indicate how and where it uses them. A variable name consists of one or more parts, separated by hyphens. Each part consists of one or more words separated by underscores.

--unity-{group}-{role_and_control}-{sub_element}-{pseudo_state_sequence}

Each part of the name tells you something about the types of USS rules that use the variable.

  • Group: the kind of data the variable represents.
  • Role/Control: a conceptual grouping for the elements the variable affects.
  • Sub-Element: the part of an element or control the variable affects.
  • Pseudo States: lists the states Unity uses the variable for.

For example, the following variable name:

--unity-colors-button-text-hover

Provides the following information about how Unity uses the variable:

Value: Meaning:
Group colors The variable represents color data.
Role/Control button The variable affects buttons.
Sub-Element text The variable affects text. Because its group is colors, you know it affects text color.
Pseudo-States hover Unity uses the variable in styles that it applies to elements when the mouse pointer hovers over them.

In other words, Unity uses this variable in styles that change the color of button text when a user hovers over the button.

The rest of this section provides detailed information about each part of the variable name format.

Group

The group specifies what kind of data the variable represents. Each group has several possible sub-elements.

Unity variable names can have the following groups:

Group: Used for:
colors Color properties, such as background-color and border-color
metrics Properties that control dimensions and shapes. For example, border-radius, border-width, margin, and padding
icons Standard Unity icon images

Role and Control

Roles and controls are two ways of grouping elements conceptually.

  • Role refers to a group of elements that have the same purpose, regardless of what type each element is. For example, the error role includes all elements that are involved in displaying an error message to users.
  • Control refers to a group of elements of the same type, regardless of what they do. For example, buttons includes all buttons in the editor.

Every Unity variable has either a role or a control. It cannot have both.

Unity variable names can have the following roles and controls:

Roles:

Role: Description:
default Default style settings such as text color, background, and margin.
alternated_rows Elements that display tabular data with alternating row colors. For example, list items in a list view.
error Elements that communicate error states to users.
highlight Highlighted parts of the UI. For example, text selections, or selected items in tree views.
link Parts of the UI (typically text) that are clickable links. This is the un-clicked state.
play_mode Elements displayed when the Editor is in Play mode.
visited_link Parts of the UI, typically text, that are clickable links that a user has already clicked.
warning Elements that communicate a warning message to users.

Controls:

Control: Description:
app_toolbar The main Unity toolbarA row of buttons and basic controls at the top of the Unity Editor that allows you to interact with the Editor in various ways (e.g. scaling, translation). More info
See in Glossary
app_toolbar_button Buttons in the main Unity toolbar
box Boxes used to group elements in the Editor UI
button Buttons in the UI, except for toolbars
dropdown Dropdown lists or menus
helpbox Boxes used to display help information
input_field Fields used to input text or numeric values
label Text labels in the Editor UI
object_field Fields used for object values. For example, property values for a GameObjectThe fundamental object in Unity scenes, which can represent characters, props, scenery, cameras, waypoints, and more. A GameObject’s functionality is defined by the Components attached to it. More info
See in Glossary
or Asset.
popup Popup menu and other popup controls
preview Views used to display previews. For example, of Assets such as meshes and textures.
scrollbar_groove The background element of a scrollbar in which users drag the scrollbar thumb
scrollbar_thumb The draggable handle element in a scrollbar
slider_groove The background element of a slider in which users drag the slider thumb
slider_thumb The draggable handle element in a slider
slider_thumb_halo An overlay displayed around the slider thumb when the user drags it
tab Tab items in tab controls
toolbar Any Editor toolbar except for the main Unity toolbar (app_toolbar)
toolbar_button Buttons in an Editor toolbar
window Editor windows

Sub-Element

The sub-element is the part of an element that the variable affects. Together with a variable’s group, the sub-element tells you exactly what kind of data the variable represents.

For example, when you see a variable name with the colors group and the text sub-element, it means Unity uses the variable in styles that affect text color.

Unity variable names can have the following sub-elements:

Group: Sub-element: Description:
colors
background An element’s background color
border An element’s outer border color
border_accent An element’s inner border color. For example, InspectorA Unity window that displays information about the currently selected GameObject, asset or project settings, allowing you to inspect and edit the values. More info
See in Glossary
windows have a two-tone border
text Text color for elements that display text
metrics
margin_{left, top, right, bottom} An element’s margin values
padding_{left, top, right, bottom} An element’s padding values
border_{left, top, right, bottom}_width An element’s border width values
border_{left_top, left_bottom, right_top, right_bottom}_radius An element’s border radius values values
width, height An element’s width and height values

Pseudo-States

The pseudo-state sequence is a list of UI states that Unity uses a variable for.

For example, when you see a variable name with the hover pseudo state, it means Unity uses the variable in styles that affect elements when a user hovers the pointer over them.

For example: --unity-colors-toolbar_button-text-hover.

A variable name can have more than one pseudo-state. Multiple pseudo states appear in alphabetical order, separated by underscores _.

For example: --unity-colors-toolbar_button-text-focus_selected.

Unity variable names can have any combination of the following pseudo-states:

Pseudo-state: Description:
(none) Normal state
checked A checkbox-type control is checked
disabled A control is disabled
focus A control has focus
hover A user hovers over a control
inactive A control does not have focus
pressed A control is pressed
selected A control is selected

List of built-in Unity variables

Group Role/Control Name Description Dark Theme Light Theme Runtime Theme
metrics
--unity-metrics-default-border_radius The default border radius for controls 3px 3px Undefined
--unity-metrics-inspector_titlebar-height The height of a title bar in an Inspector view 22px 22px Undefined
--unity-metrics-single_line-height The usual height for a single-line Editor control, for example, a one-line text field. See EditorGUIUtility.singleLineHeight 18px 18px 18px
--unity-metrics-single_line_large-height The usual height for a large single-line Editor control, for example, an Inspector title bar label 20px 20px 20px
--unity-metrics-single_line_small-height The usual height for a small single-line Editor control, for example, a mini toggle or a mini text field 16px 16px 16px
--unity-metrics-toolbar-height The height of a toolbar control 21px 21px Undefined
--unity-metrics-toolbar_button-height The height of a toolbar button control 20px 20px Undefined
colors
alternated_rows
--unity-colors-alternated_rows-background The alternate background color for views with alternating row colors #3F3F3F #CACACA Undefined
app_toolbar
--unity-colors-app_toolbar-background The background color for the main toolbar #191919 #8A8A8A Undefined
app_toolbar_button
--unity-colors-app_toolbar_button-background The background color for a button in the main toolbar #383838 #C8C8C8 Undefined
--unity-colors-app_toolbar_button-background-checked The background color for a button in the main toolbar when it is checked #6A6A6A #656565 Undefined
--unity-colors-app_toolbar_button-background-hover The background color for a button in the main toolbar when the mouse pointer hovers over them #424242 #BBBBBB Undefined
--unity-colors-app_toolbar_button-background-pressed The background color for a button in the main toolbar when it is pressed #6A6A6A #656565 Undefined
--unity-colors-app_toolbar_button-border The border color for a button in the main toolbar #191919 #6B6B6B #6B6B6B
--unity-colors-app_toolbar_button-border_accent The accent border color for a button in the main toolbar #222222 #6B6B6B Undefined
box
--unity-colors-box-background The background color for a box control rgba(40, 40, 40, 0.3019608) rgba(185, 185, 185, 0.9019608) #DEDEDE
--unity-colors-box-border The border color for a box control transparent transparent #555555
button
--unity-colors-button-background The background color for a button control #585858 #E4E4E4 #E4E4E4
--unity-colors-button-background-focus The background color for a button control when it has focus #6E6E6E #BEBEBE Undefined
--unity-colors-button-background-hover The background color for a button control when the mouse pointer hovers over it #676767 #ECECEC #ECECEC
--unity-colors-button-background-pressed The background color for a button control when it is pressed #353535 #B1B1B1 #6F6F6F
--unity-colors-button-border The border color for a button control #303030 #B2B2B2 Undefined
--unity-colors-button-border_accent The border accent color for a button control #242424 #939393 Undefined
--unity-colors-button-border-pressed The border color for a button control when it is pressed #0D0D0D #707070 Undefined
--unity-colors-button-text The text color for a button control #EEEEEE #090909 #101010
default
--unity-colors-default-background The default background color for controls #282828 #A5A5A5 Undefined
--unity-colors-default-border The default border color for controls #232323 #999999 Undefined
--unity-colors-default-text The default text color #D2D2D2 #090909 #101010
--unity-colors-default-text-hover The default text color when the mouse pointer hovers over the text #BDBDBD #090909 Undefined
dropdown
--unity-colors-dropdown-background The background color for a dropdown control #515151 #DFDFDF #DFDFDF
--unity-colors-dropdown-background-hover The background color for a dropdown control when the mouse pointer hovers over it #585858 #E4E4E4 #E8E8E8
--unity-colors-dropdown-border The border color for a dropdown control #303030 #B2B2B2 #999999
--unity-colors-dropdown-border_accent The border accent color for a dropdown control #242424 #939393 Undefined
--unity-colors-dropdown-text The text color for a dropdown control #E4E4E4 #090909 #101010
error
--unity-colors-error-text The text color for error messages #D32222 #5A0000 Undefined
helpbox
--unity-colors-helpbox-background The background color for a helpbox control rgba(96, 96, 96, 0.2039216) rgba(235, 235, 235, 0.2039216) Undefined
--unity-colors-helpbox-border The border color for a helpbox control #232323 #A9A9A9 Undefined
--unity-colors-helpbox-text The text color for a helpbox control #BDBDBD #161616 Undefined
highlight
--unity-colors-highlight-background The background color for selected items or selected text #2C5D87 #3A72B0 Undefined
--unity-colors-highlight-background-hover The background color for items when the mouse pointer hovers over them rgba(256, 256, 256, 0.0627451) rgba(0, 0, 0, 0.0627451) Undefined
--unity-colors-highlight-background-inactive The background color for selected items or selected text when the control does not have focus #4D4D4D #AEAEAE Undefined
--unity-colors-highlight-text The text color for selected items or selected text #4C7EFF #0032E6 Undefined
--unity-colors-highlight-text-inactive The text color for selected items or selected text when the control does not have focus #FFFFFF #FFFFFF Undefined
input_field
--unity-colors-input_field-background The background color for an input field control #2A2A2A #F0F0F0 #F0F0F0
--unity-colors-input_field-border The border color for an input field control #212121 #B7B7B7 #A0A0A0
--unity-colors-input_field-border_accent The border accent color for an input field control #0D0D0D #A0A0A0 Undefined
--unity-colors-input_field-border-focus The border color for an input field control when it has focus #3A79BB #1D5087 #0C6CCB
--unity-colors-input_field-border-hover The border color for an input field control when the mouse pointer hovers over it #656565 #6C6C6C #6C6C6C
inspector_titlebar
--unity-colors-inspector_titlebar-background The background color for a title bar in an Inspector view #3E3E3E #CBCBCB Undefined
--unity-colors-inspector_titlebar-background-hover The background color for a title bar in an Inspector view when the mouse pointer hovers over it #474747 #D6D6D6 Undefined
--unity-colors-inspector_titlebar-border The border color for a title bar in an Inspector view #1A1A1A #7F7F7F Undefined
--unity-colors-inspector_titlebar-border_accent The border accent color for a title bar in an Inspector view #303030 #BABABA Undefined
label
--unity-colors-label-text The text color for a label control #C4C4C4 #090909 #3B3B3B
--unity-colors-label-text-focus The text color for a label when it has focus #81B4FF #003C88 #074492
link
--unity-colors-link-text The text color for unvisited links #4C7EFF #4C7EFF Undefined
object_field
--unity-colors-object_field-background The background color for an object field control #282828 #EDEDED #EDEDED
--unity-colors-object_field-border The border color for an object field control #202020 #B0B0B0 #A0A0A0
--unity-colors-object_field-border-focus The border color for an object field control when it has focus #3A79BB #1D5087 #0C6CCB
--unity-colors-object_field-border-hover The border color for an object field control when the mouse pointer hovers over it #656565 #6C6C6C #6C6C6C
object_field_button
--unity-colors-object_field_button-background The background color for the button in an object field control #373737 #DEDEDE #DEDEDE
--unity-colors-object_field_button-background-hover The background color for the button in an object field control when the mouse pointer hovers over it #4C4C4C #CCCCCC #CCCCCC
play_mode
--unity-colors-play_mode-background The color used to tint the UI in Play Mode #606060 #ECECEC Undefined
popup
--unity-colors-popup-background The background color for a popup window #313131 #C1C1C1 Undefined
preview
--unity-colors-preview-background The background color for a preview control #313131 #C1C1C1 Undefined
--unity-colors-preview-border The border color for a preview control #232323 #999999 Undefined
--unity-colors-preview-text The text color for a preview control #BDBDBD #090909 Undefined
preview_overlay
--unity-colors-preview_overlay-text The text color for a preview control overlay #DEDEDE #FFFFFF Undefined
progress
--unity-colors-progress-background #303030 #606060 Undefined
scrollbar_button
--unity-colors-scrollbar_button-background The background color for a scrollbar’s scroll buttons rgba(0, 0, 0, 0.05098039) rgba(0, 0, 0, 0.05098039) Undefined
--unity-colors-scrollbar_button-background-hover The background color for a scrollbar’s scroll buttons when the mouse pointer hovers over them #494949 #A7A7A7 Undefined
scrollbar_groove
--unity-colors-scrollbar_groove-background The background color for a scrollbar’s groove (background) rgba(0, 0, 0, 0.05098039) rgba(0, 0, 0, 0.05098039) Undefined
--unity-colors-scrollbar_groove-border The border color for a scrollbar’s groove rgba(0, 0, 0, 0.1019608) rgba(0, 0, 0, 0.1019608) Undefined
scrollbar_thumb
--unity-colors-scrollbar_thumb-background The background color for a scrollbar’s thumb/handle #5F5F5F #9A9A9A #9A9A9A
--unity-colors-scrollbar_thumb-background-hover The background color for a scrollbar’s thumb/handle when the mouse pointer hovers over it #686868 #8E8E8E #8E8E8E
--unity-colors-scrollbar_thumb-border The border color for a scrollbar’s thumb/handle #323232 #B9B9B9 #9A9A9A
--unity-colors-scrollbar_thumb-border-hover The border color for a scrollbar’s thumb/handle when the mouse pointer hovers over it #686868 #8E8E8E Undefined
slider_groove
--unity-colors-slider_groove-background The background color for a slider’s groove (background) #5E5E5E #8F8F8F #8F8F8F
--unity-colors-slider_groove-background-disabled The background color for a slider’s groove when it is disabled #575757 #A4A4A4 #A4A4A4
slider_thumb
--unity-colors-slider_thumb-background The background color for a slider’s thumb/handle #999999 #616161 #616161
--unity-colors-slider_thumb-background-disabled The background color for a slider’s thumb/handle when it is disabled #666666 #9B9B9B #9B9B9B
--unity-colors-slider_thumb-background-hover The background color for a slider’s thumb/handle when the mouse pointer hovers over it #EAEAEA #4F4F4F #4F4F4F
--unity-colors-slider_thumb-border The border color for a slider’s thumb #999999 #616161 #616161
--unity-colors-slider_thumb-border-disabled The border color for a slider’s thumb when it is disabled #666666 #666666 #9B9B9B
slider_thumb_halo
--unity-colors-slider_thumb_halo-background The background color for a slider’s thumb halo rgba(16, 111, 205, 0.5019608) rgba(12, 108, 203, 0.5019608) Undefined
tab
--unity-colors-tab-background The background color for an Editor window tab #353535 #B6B6B6 Undefined
--unity-colors-tab-background-checked The background color for an Editor window tab when it is selected #3C3C3C #CBCBCB Undefined
--unity-colors-tab-background-hover The background color for an Editor window tab when the mouse pointer hovers over it #303030 #B0B0B0 Undefined
--unity-colors-tab-text The text color for an Editor window tab #BDBDBD #090909 Undefined
toolbar
--unity-colors-toolbar-background The background color for a toolbar control #3C3C3C #CBCBCB #CBCBCB
--unity-colors-toolbar-border The border color for a toolbar control #232323 #999999 Undefined
toolbar_button
--unity-colors-toolbar_button-background The background color for a toolbar button control #3C3C3C #CBCBCB #CBCBCB
--unity-colors-toolbar_button-background-checked The background color for a toolbar button control when it is checked #505050 #EFEFEF #E1E1E1
--unity-colors-toolbar_button-background-focus The background color for a toolbar button control when it has focus #464646 #C1C1C1 #E1E1E1
--unity-colors-toolbar_button-background-hover The background color for a toolbar button control when the mouse pointer hovers over it #464646 #C1C1C1 #C1C1C1
--unity-colors-toolbar_button-border The border color for a toolbar button control #232323 #999999 #999999
--unity-colors-toolbar_button-text The text color for a toolbar button control #C4C4C4 #090909 #101010
--unity-colors-toolbar_button-text-checked The text color for a toolbar button control when it is checked #C4C4C4 #090909 #101010
--unity-colors-toolbar_button-text-hover The text color for a toolbar button control #BDBDBD #090909 #101010
visited_link
--unity-colors-visited_link-text The text color for visited links #FF00FF #AA00AA Undefined
warning
--unity-colors-warning-text The text color for warning messages #F4BC02 #333308 Undefined
window
--unity-colors-window-background The background color for a window #383838 #C8C8C8 Undefined
--unity-colors-window-border The border color for a window #242424 #939393 Undefined
--unity-colors-window-text The text color for a window #BDBDBD #090909 #101010
icons
--unity-icons-arrow_left Builtin Skins/DarkSkin/Images/ArrowNavigationLeft.png Builtin Skins/LightSkin/Images/ArrowNavigationLeft.png Undefined
--unity-icons-arrow_right Builtin Skins/DarkSkin/Images/ArrowNavigationRight.png Builtin Skins/LightSkin/Images/ArrowNavigationRight.png Undefined
--unity-icons-clear UIPackageResources/Images/d_clear.png UIPackageResources/Images/clear.png Undefined
--unity-icons-color_picker UIPackageResources/Images/d_color_picker.png UIPackageResources/Images/color_picker.png Undefined
--unity-icons-console_entry_error Icons/d_console.erroricon.png Icons/console.erroricon.png Undefined
--unity-icons-console_entry_error_small Icons/d_console.erroricon.sml.png Icons/console.erroricon.sml.png Undefined
--unity-icons-console_entry_info Icons/d_console.infoicon.png Icons/console.infoicon.png Undefined
--unity-icons-console_entry_info_small Icons/d_console.infoicon.sml.png Icons/console.infoicon.sml.png Undefined
--unity-icons-console_entry_warn Icons/d_console.warnicon.png Icons/console.warnicon.png Undefined
--unity-icons-console_entry_warn_small Icons/d_console.warnicon.sml.png Icons/console.warnicon.sml.png Undefined
--unity-icons-dropdown UIPackageResources/Images/d_dropdown.png UIPackageResources/Images/dropdown.png Undefined
--unity-icons-dropdown_toggle UIPackageResources/Images/d_dropdown_toggle.png UIPackageResources/Images/dropdown_toggle.png Undefined
--unity-icons-foldout UIPackageResources/Images/d_IN_foldout.png UIPackageResources/Images/IN_foldout.png Undefined
--unity-icons-foldout-checked UIPackageResources/Images/d_IN_foldout_on.png UIPackageResources/Images/IN_foldout_on.png Undefined
--unity-icons-foldout-checked_focus UIPackageResources/Images/d_IN_foldout_focus_on.png UIPackageResources/Images/IN_foldout_focus_on.png Undefined
--unity-icons-foldout-checked_pressed UIPackageResources/Images/d_IN_foldout_act_on.png UIPackageResources/Images/IN_foldout_act_on.png Undefined
--unity-icons-foldout-focus UIPackageResources/Images/d_IN_foldout_focus.png UIPackageResources/Images/IN_foldout_focus.png Undefined
--unity-icons-foldout-pressed UIPackageResources/Images/d_IN_foldout_act.png UIPackageResources/Images/IN_foldout_act.png Undefined
--unity-icons-link Icons/d_UnLinked.png Icons/UnLinked.png Undefined
--unity-icons-link-checked Icons/d_Linked.png Icons/Linked.png Undefined
--unity-icons-lock Builtin Skins/DarkSkin/Images/IN LockButton.png Builtin Skins/LightSkin/Images/IN LockButton.png Undefined
--unity-icons-lock-checked Builtin Skins/DarkSkin/Images/IN LockButton on.png Builtin Skins/LightSkin/Images/IN LockButton on.png Undefined
--unity-icons-lock-checked_pressed Builtin Skins/DarkSkin/Images/IN LockButton on act.png Builtin Skins/LightSkin/Images/IN LockButton on act.png Undefined
--unity-icons-lock-pressed Builtin Skins/DarkSkin/Images/IN LockButton act.png Builtin Skins/LightSkin/Images/IN LockButton act.png Undefined
--unity-icons-minus UIPackageResources/Images/d_ol_minus.png UIPackageResources/Images/ol_minus.png Undefined
--unity-icons-minus-hover UIPackageResources/Images/d_ol_minus_act.png UIPackageResources/Images/ol_minus_act.png Undefined
--unity-icons-pane_options Builtin Skins/DarkSkin/Images/pane options.png Builtin Skins/LightSkin/Images/pane options.png Undefined
--unity-icons-picker UIPackageResources/Images/d_pick.png UIPackageResources/Images/pick.png Undefined
--unity-icons-plus UIPackageResources/Images/d_ol_plus.png UIPackageResources/Images/ol_plus.png Undefined
--unity-icons-plus-hover UIPackageResources/Images/d_ol_plus_act.png UIPackageResources/Images/ol_plus_act.png Undefined
--unity-icons-profiler_timeline_digdown_arrow Profiler/d_ProfilerTimelineDigDownArrow.png Profiler/ProfilerTimelineDigDownArrow.png Undefined
--unity-icons-profiler_timeline_rollup_arrow Profiler/d_ProfilerTimelineRollUpArrow.png Profiler/ProfilerTimelineRollUpArrow.png Undefined
--unity-icons-pulldown UIPackageResources/Images/d_dropdown.png UIPackageResources/Images/dropdown.png Undefined
--unity-icons-scroll_down UIPackageResources/Images/d_scrolldown.png UIPackageResources/Images/scrolldown.png Undefined
--unity-icons-scroll_left UIPackageResources/Images/d_scrollleft.png UIPackageResources/Images/scrollleft.png Undefined
--unity-icons-scroll_right UIPackageResources/Images/d_scrollright.png UIPackageResources/Images/scrollright.png Undefined
--unity-icons-scroll_up UIPackageResources/Images/d_scrollup.png UIPackageResources/Images/scrollup.png Undefined
--unity-icons-search UIPackageResources/Images/d_search_icon.png UIPackageResources/Images/search_icon.png Undefined
--unity-icons-search_menu UIPackageResources/Images/d_search_menu.png UIPackageResources/Images/search_menu.png Undefined
--unity-icons-shuriken_toggle-checked Builtin Skins/DarkSkin/Images/ShurikenToggleNormalOn.png Builtin Skins/LightSkin/Images/ShurikenToggleNormalOn.png Undefined
--unity-icons-shuriken_toggle-checked_focus Builtin Skins/DarkSkin/Images/ShurikenToggleFocusedOn.png Builtin Skins/LightSkin/Images/ShurikenToggleFocusedOn.png Undefined
--unity-icons-shuriken_toggle-checked_hover Builtin Skins/DarkSkin/Images/ShurikenToggleHoverOn.png Builtin Skins/LightSkin/Images/ShurikenToggleHoverOn.png Undefined
--unity-icons-shuriken_toggle_bg Builtin Skins/DarkSkin/Images/ShurikenToggleNormal.png Builtin Skins/LightSkin/Images/ShurikenToggleNormal.png Undefined
--unity-icons-shuriken_toggle_bg-focus Builtin Skins/DarkSkin/Images/ShurikenToggleFocused.png Builtin Skins/LightSkin/Images/ShurikenToggleFocused.png Undefined
--unity-icons-shuriken_toggle_bg-focus_mixed Builtin Skins/DarkSkin/Images/ShurikenToggleFocusedMixed.png Builtin Skins/LightSkin/Images/ShurikenToggleFocusedMixed.png Undefined
--unity-icons-shuriken_toggle_bg-hover Builtin Skins/DarkSkin/Images/ShurikenToggleHover.png Builtin Skins/LightSkin/Images/ShurikenToggleHover.png Undefined
--unity-icons-shuriken_toggle_bg-hover_mixed Builtin Skins/DarkSkin/Images/ShurikenToggleHoverMixed.png Builtin Skins/LightSkin/Images/ShurikenToggleHoverMixed.png Undefined
--unity-icons-shuriken_toggle_bg-mixed Builtin Skins/DarkSkin/Images/ShurikenToggleNormalMixed.png Builtin Skins/LightSkin/Images/ShurikenToggleNormalMixed.png Undefined
--unity-icons-toggle-checked UIPackageResources/Images/d_toggle_on.png UIPackageResources/Images/toggle_on.png Undefined
--unity-icons-toggle-checked_focus UIPackageResources/Images/d_toggle_on_focus.png UIPackageResources/Images/toggle_on_focus.png Undefined
--unity-icons-toggle-checked_hover UIPackageResources/Images/d_toggle_on_hover.png UIPackageResources/Images/toggle_on_hover.png Undefined
--unity-icons-toggle-focus_mixed UIPackageResources/Images/d_toggle_on_focus.png UIPackageResources/Images/toggle_on_focus.png Undefined
--unity-icons-toggle-hover_mixed UIPackageResources/Images/d_toggle_on_hover.png UIPackageResources/Images/toggle_on_hover.png Undefined
--unity-icons-toggle-mixed UIPackageResources/Images/d_toggle_on.png UIPackageResources/Images/toggle_on.png Undefined
--unity-icons-toggle_bg UIPackageResources/Images/d_toggle_bg.png UIPackageResources/Images/toggle_bg.png Undefined
--unity-icons-toggle_bg-focus UIPackageResources/Images/d_toggle_bg_focus.png UIPackageResources/Images/toggle_bg_focus.png Undefined
--unity-icons-toggle_bg-focus_mixed UIPackageResources/Images/d_toggle_mixed_bg_focus.png UIPackageResources/Images/toggle_mixed_bg_focus.png Undefined
--unity-icons-toggle_bg-hover UIPackageResources/Images/d_toggle_bg_hover.png UIPackageResources/Images/toggle_bg_hover.png Undefined
--unity-icons-toggle_bg-hover_mixed UIPackageResources/Images/d_toggle_mixed_bg_hover.png UIPackageResources/Images/toggle_mixed_bg_hover.png Undefined
--unity-icons-toggle_bg-mixed UIPackageResources/Images/d_toggle_mixed_bg.png UIPackageResources/Images/toggle_mixed_bg.png Undefined
--unity-icons-window_button_close Icons/d_winbtn_win_close.png Icons/winbtn_win_close.png Undefined
--unity-icons-window_button_max Icons/d_winbtn_win_max.png Icons/winbtn_win_max.png Undefined
--unity-icons-window_button_restore Icons/d_winbtn_win_restore.png Icons/winbtn_win_restore.png Undefined

USS custom properties (variables)
Write style sheets