Double primary colour wheel based on the RYB colour model, Shillito Design School, featuring Cadmium Yellow, Lemon Yellow, Prussian Blue, Ultramarine, Carmine and Vermilion. Colour models like this are visual tools intended to prompt an understanding of the range of hue possibilities. They are not intended to represent the complexity of colour in any way but as a starting point to explore colour nuances and relationships. Image: Zena O’Connor and Geoffrey Gifford, 2021.