At the core of the colour wheel are three primary colours - Red, Yellow and Blue. The primary colours are unique and cannot be created by mixing any other colours. When mixing these 3 colour hues, at least in theory, all the other hues of the colour wheel, including black can be created.
Primaries form the ultimate contrast of hue and have the greatest luminosity. Primaries express fundamental qualities, folk art, embroidery, costumes, etc. They are exuberant, decorative, tonic, vigorous, decisive.
Next on the colour wheel are the secondary or complementary colours. Three secondary colours are produced by mixing one primary colour with another. These colours are Orange, Green and Violet.
Secondaries form the second most contrast of hue. The intensity of these colours is relatively diminished as hues are further away from the primaries.
Tertiary colours are created by mixing one secondary and one primary colour. E.g. blue + violet = blue-violet.
Three or more separate colours are mixed (one primary and one secondary - the combination of two primaries), and in the colour wheel each tertiary colour being created will be an equal combination of the two colours, left and right, one being a primary and the other, a secondary. The tertiary colours are yellow-orange, red-orange, red-violet, blue-violet, blue-green and yellow-green.
Tertiary colours have less distinctive colour contrasts and often represent the concrete, mundane, and earthly simplicity. They are associated with cosmic universality, celestial, medieval manuscripts, stained glass, and other religious art.
Contrasting colours separated by two or three colours on the wheel create bold, vivid images. They have a huge impact on the appearance of the main colour. Here, the middle squares are actually the same shade of red. Setting one against a green background makes it seem redder than the square set against orange.
The colours opposite to each other on a colour wheel are complementary colours, while analogous colours lie adjacent to each other on the wheel. Complementary colours (blue and orange) create exciting, even vibrating effects. In contrast, an analogous colour harmony (blue and blue-green) is less vivid, even calming.