I went with the mnemonic I learned long ago, ROY G. BIV, to represent the colors red, orange, yellow, green, blue, indigo, and violet. Some sources state that indigo is no longer accepted, some include cyan, and some include neither, but I like the seven-color representation shown here.
Color | Wavelength (nm) | Frequency (THz) |
---|---|---|
Red | 620-750 | 400-484 |
Orange | 590-620 | 484-508 |
Yellow | 570-590 | 508-526 |
Green | 495-570 | 526-606 |
Blue | 450-495 | 606-668 |
Indigo | 420-450 | 668-720 |
Violet | 380-420 | 720-789 |