4 Types Of Colours (People)

The colours of a aurora boralis are pink, green, yellow, blue, violet, and occasionally orange and white.

• When the particles mix with oxygen, yellow and green are produced.
• When the particles interact with nitrogen, red, violet, and blue colours are produce...

• The colour-sensitive receptors that humans have, called melanopsin, measure the amount of blue or yellow light in the atmosphere and likewise regulate our circadian rhythm.
• Human beings have Cone Cells, which are of three types, Red, Blue, and Green

When you're using an acronym or image to recall something, you're using a mnemonic. 

Example: The hall of fame includes abbreviations — Roy G. Biv for the colors of the spectrum ( Red, Orange, Yellow, Green, Blue, Indigo, Violet) — and rhyming, like "in 1492, Columbus sailed the o...