How to Change transparency of button image in Unity 5.0?

Question

I would like to change the transparency of button image from the script (written in C#). What is the best way to do it?

Answer 1

Here the script version!

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

            public class SetTransparancy : MonoBehaviour {
                public Button myButton;
                // Use this for initialization
                void Start () {
                    myButton.image.color = new Color(255f,0f,0f,.5f);
                }

                // Update is called once per frame
                void Update () {

                }
            }

I tested it in Unity5