TextureFormat.ARGB32

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
	void Start() {
		Texture2D texture = new Texture2D(128, 128, TextureFormat.ARGB32, false);
		renderer.material.mainTexture = texture;
	}
}

function Start () {
	// Create a new RGB texture and assign it to the renderer's material
	//创建一个新的RGB纹理格式，并制定到渲染器材质
	var texture = new Texture2D (128, 128, TextureFormat.ARGB32, false);
	renderer.material.mainTexture = texture;
}