A colour wheel shows red, yellow and blue as the original primary colours. They are called ‚primary‘ because you cannot mix them from other colours. Looking at your colour wheel you will see that secondary colours are made by combining two primary colours which results in orange, green and violet. You can produce a large variety of different colour shades depending on the proportions in which you mix the two primaries, with all of them excelling in the same level of beauty and brilliancy. Any two colours which lie opposite each other on the colour wheel are called complementary colours. Mixing complementary colours will give you a grey. Black, white and grey show nowhere on the colour wheel and are called achromatic colours.