Colours can be classified into primary, secondary, tertiary and neutral. Primary colours are pure hues. This means that they cannot be created by mixing colours. Secondary colours are created by mixing primary colours and tertiary colours are created by mixing primary and secondary colours.
The three primary colours are yellow, red and blue. With these three colours many other colours can be created. If more white is added to a primary colour, this is called a tint. If more black is added, this is called a shade. If grey is added, the colour acquires a different tone.
The secondary colours are orange, purple and green. Orange is a mixture of yellow and red. Purple is a mixture of red and blue and green is a mixture of blue and yellow.
Tertiary colours are a combination of a primary and a secondary colour. Brown is created by mixing the primary colour red with the secondary colour green.
The neutral colours are white, black and grey. White and black are opposites. White is bright but black is dark. In a certain sense, black and white are not colours because black can be considered the absence of light and white is the blending of many bright colours. Black can be created by mixing many colours. A combination of the primary colours yellow, red and blue can create black.
Though the primary colours are limited to three, they can be used to create many other colours. These include the secondary and tertiary colours. Other colours are the neutral colours which can be combined with primary and secondary colours to create a tint or shade and even a different tone.