10-11-2003, 10:06 PM
Additive is when different colours of light add together to give a new colour. That's what happens with computer monitors. Every colour there is represented by some quantity of red, green and blue.
The other system is subtractive, with different colours blocking out more of the light. That's what happens with printed materials; you start with white paper and print varying amounts of yellow, cyan and magenta (also black, in many cases) to get all the different colours. Subtractive is also used when mixing paints and pigments.
Red, yellow and blue are not primary colours. However, as red is sort of like magenta and blue is sort of like cyan (depending on the specific hue of red and blue), so those approximate the subtractive system.
The other system is subtractive, with different colours blocking out more of the light. That's what happens with printed materials; you start with white paper and print varying amounts of yellow, cyan and magenta (also black, in many cases) to get all the different colours. Subtractive is also used when mixing paints and pigments.
Red, yellow and blue are not primary colours. However, as red is sort of like magenta and blue is sort of like cyan (depending on the specific hue of red and blue), so those approximate the subtractive system.