What is your most favorite color in the rainbow?

Very few people can see indigo. That is the color of eggplant/aubergine, "blue" corn, and "blue" jeans. If you look at an actual rainbow you probably will see a blank space between blue and violet. The color does not exist at all in a monitor or a printer.

There is no color called purple. It is an illusion, a combination of red and blue.