GUI texture updating in preview but not in game

I’m trying to make a main menu screen, but when I hover over the “Play Game” or “Quit” button, the color changes in preview but not in game. Here’s the code I’m using. I don’t use a function update because the OnMouseEnter and OnMouseExit beacuse they should be self updating. Please help, thanks!

var isQuitButton = false ; 

 function OnMouseOver()
{
    renderer.material.color = Color.green;
}
 
 
 function OnMouseExit()
 {
    	renderer.material.color = Color.black;
}
function OnMouseUp()
{
	//are we dealing with a quit button
	if( isQuitButton)
	{
		//quit the game
		Application.Quit();
	}
	
	else 
	{
		//load level
		Application.LoadLevel(1);
	}
}

try to use the text mesh component to change the color.
so it looks something like:

#pragma strict

var isQuitButton : boolean = false;
var textMesh : TextMesh = null;

function Start() {
	textMesh = gameObject.GetComponent(TextMesh);
}

function OnMouseOver() {
	textMesh.color = Color.green;
	if (Input.GetButton ("Fire 1")) {
		textMesh.color = Color.white;
	}
	if (Input.GetButtonUp("Fire 1")) {
		if (isQuitButton) {
			Application.Quit();
		}
		else {
			Application.LoadLevel(1);
		}
	}
}

function OnMouseExit() {
	textMesh.color = Color.black;
}

i hope that this solved your problem