The material used for the font display.

	// Swap 3D Text font color each second
	// Add this script to a text mesh object
	private var flag : boolean = false;
	private var rate : float = 1;
	private var t : TextMesh;
	function Update() {
		t = transform.GetComponent(TextMesh);
		if(Time.time > rate) {
			if(flag){
				t.font.material.color = Color.yellow;
				flag = false;
			} else {
				t.font.material.color = Color.red;
				flag = true;
			}
			rate += 1;
		}
		t.text = "This is a 3D text changing colors!";
	}

using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    private bool flag = false;
    private float rate = 1;
    private TextMesh t;
    void Update() {
        t = transform.GetComponent<TextMesh>();
        if (Time.time > rate) {
            if (flag) {
                t.font.material.color = Color.yellow;
                flag = false;
            } else {
                t.font.material.color = Color.red;
                flag = true;
            }
            rate += 1;
        }
        t.text = "This is a 3D text changing colors!";
    }
}

import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	private flag as bool = false

	private rate as float = 1

	private t as TextMesh

	def Update() as void:
		t = transform.GetComponent[of TextMesh]()
		if Time.time > rate:
			if flag:
				t.font.material.color = Color.yellow
				flag = false
			else:
				t.font.material.color = Color.red
				flag = true
			rate += 1
		t.text = 'This is a 3D text changing colors!'