// ping-pong animate background color
var color1 : Color = Color.red;
var color2 : Color = Color.blue;
var duration = 3.0;

// Set clear flags to color
camera.clearFlags = CameraClearFlags.SolidColor;

function Update () {
    var t : float = Mathf.PingPong (Time.time, duration) / duration;
    camera.backgroundColor = Color.Lerp (color1, color2, t);
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    public Color color1 = Color.red;
    public Color color2 = Color.blue;
    public float duration = 3.0F;
    void Update() {
        float t = Mathf.PingPong(Time.time, duration) / duration;
        camera.backgroundColor = Color.Lerp(color1, color2, t);
    }
    void Example() {
        camera.clearFlags = CameraClearFlags.SolidColor;
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    public color1 as Color = Color.red

    public color2 as Color = Color.blue

    public duration as single = 3.0F

    def Update():
        t as single = (Mathf.PingPong(Time.time, duration) / duration)
        camera.backgroundColor = Color.Lerp(color1, color2, t)

    def Example():
        camera.clearFlags = CameraClearFlags.SolidColor