Light.color

Description

Цвет источника света

To modify the light intensity you change light's color luminance. Lights always add illumination, so a light with a black color is the same as no light at all. See Also: Light component.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    public Light lt;
    void Start() {
        lt = GetComponent<Light>();
    }
    void Update() {
        lt.color -= Color.white / 2.0F * Time.deltaTime;
    }
}

Другой пример:

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    public float duration = 1.0F;
    public Color color0 = Color.red;
    public Color color1 = Color.blue;
    public Light lt;
    void Start() {
        lt = GetComponent<Light>();
    }
    void Update() {
        float t = Mathf.PingPong(Time.time, duration) / duration;
        lt.color = Color.Lerp(color0, color1, t);
    }
}