Single-process color completely changes your hair color and is great for a dramatic change or covering grays. Double-process color involves bleaching the hair before adding a new color, offering ...

A color printed from four separate printing plates. Four-color process printing uses cyan, magenta, yellow and black (CMYK) inks to produce full color reproduction. Contrast with spot color. See CMYK.

There are limits to what humans can see and how quickly they can perceive it. Some of these limits are set by the manner in which the brain processes incoming information, and it is of particular ...