Basic Studio Directing

Colour and light

Coloured light is additive

If you take a beam of white light and pass it through a prism it splits up into its component parts (red, orange, yellow, green, blue, indigo and violet). If you take all those coloured lights and mix them together you would end up with white light again.

For television we use a good approximation to those seven colours, red, green and blue. White equals all three, black equals none of them, and most other colours can be made up by mixing different amounts of these three coloured lights together.

This is the opposite of painting, which has red, yellow and blue as the primary colours (or more accurately magenta, yellow and cyan). Paint subtracts light, i.e. it prevents colours from being reflected. ...