Version: 2018.2
public UI.Selectable.Transition transition ;

Description

The type of transition that will be applied to the targetGraphic when the state changes.

using UnityEngine;
using System.Collections;
using UnityEngine.UI; // Required when Using UI elements.

public class ExampleClass : MonoBehaviour { public Button btnMain;

void SomeFunction() { //Sets the main button's transition setting to "Color Tint". btnMain.transition = Selectable.Transition.ColorTint; } }