The colour wheel designed for watercolour artists! The watercolour wheel is designed to give a clear visual picture of how 12 common colours combine to help artists mix colours. Simply align the outside colour wheel colour with any of the inside colours and the brushes point to the window showing the result. Diameter measures approximately 10". A colour wheel shows primary, secondary and tertiary colours and mixes. The Artists' colour wheel provides a visual method for illustrating and teaching the relationships of one colour to another and the results of colour mixing.