// Attach this to a gameObject that has a renderer.

if(renderer.material.HasProperty("_Color"))
renderer.material.SetColor("_Color",Color.red);

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
void Awake() {
if (renderer.material.HasProperty("_Color"))
renderer.material.SetColor("_Color", Color.red);

}
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

def Awake():
if renderer.material.HasProperty('_Color'):
renderer.material.SetColor('_Color', Color.red)