What do you call those things that can change the color of the light that a light bulb produces?

it%26#039;s for the dash in my car, i want to change the light from orange to blue, and i don%26#039;t know what they%26#039;re called so i can%26#039;t search for them help!|||I don%26#039;t believe there is anything you can change, those are either colored bulbs, or the instrutment panel is that color.