All the colors of visible light can combine to form white light.

a. True

b. False

Yes, it's true. You can see that it is true when you go outside during a summer rain and see a rainbow. That occurs when the the water acts like a lens and separates the light into its component colors. If you have gotten this far in your studies, the index of refraction through water is different for each color which is the way to explain the different colors of the rainbow.