To begin explaining colour one has to look at the basics. Everyone should know primary three from which all other colours are made: Red, blue and yellow. The secondary colours these can be combined to create are purple, orange and green. These colours compliment the primary colours: Purple and yellow, orange and blue and green and red sit opposite from each other on the colour wheel. Tertiary colours sit in-between these hues on the wheel: Yellow-green, yellow-orange, red-orange, red-purple, blue-purple and blue-green. With proper colour theory a designer can better understand and apply these colours. However, colour theory isn't just an art. Colour theory is an entire science.
Colour is the result of spectral distribution of light, which we detect with the three colour-sensors in our eyes and is then translated by the brain into what we call colour. Experimentation in the 1920s allowed us to understand the eye's response to colours, and the 1931 CIE Chromaticity Diagram plots all perc