These rainbows are caused by some of Nancy's prisms. Why is there no green in these rainbows?
I thought this one would be a challenge. The clue is the white part in the middle. White is a mixture of all the colors. In this case, each rainbow is really two rainbows that overlap. You can see the red end of one, and the blue end of the other. In the middle, the red, blue, and green mix, putting the colors back together into white light.