Mhh I do not think there is an order for its...
Maybe this command :
void FadeLightTo(string& asLightName, float afR, float afG, float afB, float afA, float afRadius, float afTime);
Changes the properties of a light.
asLightName - internal name
afR - red value
afG - green value
afB - blue value
afA - alpha value
afRadius - radius of the light. -1 means keeping the radius
afTime - time in seconds until change is done
If the three lamp are in a dark room, you can change the colors for the changes to black. But I do not think it will work ...