You might not have noticed if you’re not a digital artist, but most painting and image apps still get color mixing wrong. As ...

In art they are: red, yellow and blue. Mixing the primary colours of paint produces the secondary colours of paint: orange, purple and green. These are different to the secondary colours of light.

By combining these, however, we can perceive many different colours. By mixing red light and green light, for example, we can see yellow. If all three are mixed together we see white light.