Colors in the physical world can be any combination of wavelengths from the visible spectrum
Any visible wavelength is perceived the same as some combination of 3 basic colors (roughly blue, green, and red)
RGB = Red , Green , Blue
Each component (R, G, or B), ranges from a minimum (no intensity)
to a maximum (full intensity), typically 0.0 to 1.0.
Other color spaces:
CMY = Cyan, Magenta, Yellow
Used in print, where colors are subtractive.
Cyan = 1 - Red
Magenta = 1 - Green
Yellow = 1 - Blue
CMYK = Cyan, Magenta, Yellow, Black
Allows printing pure black better than with ordinary CMY
HSV = Hue, Saturation, Value
a.k.a. HSB = Hue, Saturation, Brightness
Closer to human concept of colors.
