// Paint red the collider we hit.
function OnControllerColliderHit(hit : ControllerColliderHit) {
hit.collider.renderer.material.color = Color.red;
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
void OnControllerColliderHit(ControllerColliderHit hit) {
hit.collider.renderer.material.color = Color.red;
}
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

def OnControllerColliderHit(hit as ControllerColliderHit):
hit.collider.renderer.material.color = Color.red