Värvikanal näitab vaatlusaluse värvikomponendi heledust. Nt rohelise värvikanali heledusele 0 vastaks värvikood G0, heledusele 100 – kuuse okka värvusega sarnane toon ja 255 oleks „täiesti“ roheline.
Increased shading has been implemented in various ways, some formats such as .png and .tga files among others using a fourth grayscale color channel as a masking layer, often called RGB32.
