Messing with the HSV Hue Spectrum

I am creating a color wheel for a color picker. I am using Hue (as in hue, saturation, value), mapping to angle of pixel, then converting to RGB. Pretty standard so far. I notice secondary and tertiary colors get a lot less real estate than the primaries. I wish I had time to build an algorithm to give these other colors more real estate, but I don't. Does anyone know if an algorithm like this already exists?