A secondary colour is a colour made by mixing two primary colours in a given colour space. The colour space may be produced by an additive colour model that involves mixing different wavelengths of light or by a subtractive colour model that involves mixing pigments or dyes.
- Secondary colours produced by an additive colour model are quite different from the spectral colours seen in a rainbow.
- A spectral colour is produced by a single wavelength, or a narrow band of wavelengths, within the visible spectrum.
- A secondary colour produced by an additive colour model results from superimposing wavelengths of light from different areas of the visible spectrum.
- For the human eye, the best additive primary colours of light are red, green, and blue.