An implementation of the hue-saturation colour model, in which the luminance is defined as the highest of the three RGB values. In this scheme pure primary and secondary colours such as blue, magenta, yellow and red are all considered to have the same brightness as white. Despite this naive approach to luminance, the HSV colour space is a popular space in colour pickers, as it separates colour properties in a way which most humans find intuitive. The Grasshopper colour picker provides access to the HSV space.