COLOUR SYSTEM Additive system is based on red, green, and blue - RGB for short. Furthermore subtractive system is based on cyan, magenta, and yellow, plus black. It is called CMYK. The additive colour works with everything that emits light. We add colour light and for this reason this system is additive. The more light you add, the brighter and lighter the colour becomes. Consequently, white is the complete combination of the three colours, whereas black is the absence of light. If we turn off the light, we get darkness. On the other hand, subtractive colour system is produced when we paint or print a surface whit ink. It is called subtractive because we subtract the colour of the support, which is usually white due to paper. However, in subtractive colour, white is the absence of colour, while black is the combination of all colours, but it’s an imperfect system. Why? The ‘K’ in CMYK stands for ‘key’, nor for black, which is the fourth colour. Black is used because the combination of the three primary colours doesn’t produce a fully saturated black. When you choose one or another colour model you should be guided by the final product. Use RGB for projects that the audience will view only on a screen, while you should use CMYK for print, brochures, posters, magazines, books, newspapers etc.