Color modes
RGB mode
The additive light
An image is obtained by superposition of three light rays : The ROUG e ( R ) the green ( V ) and blue ( B ) .
An image RGB is composed of the sum of three light rays red , green, and blue whose beams are superimposed.
The CMYK
The subtractive light
The colors are obtained by mixing pigments. When illuminated with white light, the pigments absorb part of the light they receive that makes them appear colored.
The three colors "primary" are cyan ( C ) the magenta ( M ) and yellow ( J ). The others are obtained by mixing.
Note: The ink on the paper act as filters that absorb light. Their superposition should theoretically produce a total which is black not the case in practice.
The three inks are not added more than a dark brown, we must build a fourth passage of black ink (which we note is therefore only logical: " N "as Black ).