Image.overrideSprite

Description

Set an override sprite to be used for rendering.

The overrideSprite variable allows a sprite to have the sprite changed. This change happens immediately. When the changed sprite is no longer needed the sprite can be reverted back to the original version. This happens when the overrideSprite is set to null.
Note: The script example below has two buttons. The button textures are loaded from the Resources folder. (They are not used in the shown example). Two sprites are added to the example code. Example1 and Example2 are functions called by the button OnClick functions. Example1 calls overrideSprite and Example2 sets overrideSprite to null.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class ExampleClass : MonoBehaviour
{
    private Sprite sprite1;
    private Sprite sprite2;
    private Image i;

    public void Start()
    {
        i = GetComponent<Image>();
        sprite1 = Resources.Load<Sprite>("texture1");
        sprite2 = Resources.Load<Sprite>("texture2");

        i.sprite = sprite1;
    }

    // Called by a Button OnClick() with ExampleClass.Example1
    // Uses overrideSprite to make this change temporary
    public void Example1()
    {
        i.overrideSprite = sprite2;
    }

    // Called by a Button OnClick() with ExampleClass.Example2
    // Removes the overrideSprite which causes the original sprite to be used again.
    public void Example2()
    {
        i.overrideSprite = null;
    }
}