Differences between the addition of light and the subtraction of light

The addition of light	The subtraction of light
The mixing of coloured lights to form other colours.	The absorption of specific colours from white light.
The primary coloured lights combine to form secondary coloured lights.	The primary colour filter absorbs all colours except its own colours.
All the secondary coloured lights combine to form white light.	The secondary colour filter absorbs all colours, except its own colour and the colour which forms it.