There is no color called purple. It is an optical illusion caused by mixing red and blue. Eggplant is not purple, it is indigo, same color as "blue" jeans and injun corn. The color does not exist in computer equipment, and the human eye can't see it. If you look at an actual rainbow you will see a gap between blue and violet. In pictures that is usually painted some dark shade to conceal the gap.
On the contrary, purple and violet are equivalent terms for the same colour. It's indigo that doesn't exist in it's own right, being merely a bluish shade of violet. Invented by the superstitious to make the spectrum seven, as seven was supposed to be the "perfect number."
Jewels Vern is more right. Blue, indigo and violet are visible light but purple isn't. Sorry purple, you don't get to be a real color. It's why you're evil. Embrace your inner evil, purple.
Anyway, their frequencies are:
Blue: 606 - 668 THz Indigo: 668 THz +/- a few THz Violet: 668 - 789 THz
Purple doesn't have a frequency. It's a mixture of red light and blue light.
It's why you're evil. Embrace your inner evil, purple.
Livvie 