What color space does this use? Is it HSV? You should consider moving to something more perceptually based; all these look slightly off to me.
What color space would be better than HSV? HSV- and HSL-based color pickers are intuitive, predictable and used by the majority of the designer-oriented apps: https://community.kde.org/Krita/Community_Mockups_and_Wishli...
For example, note how the hue dimension of HSV ( http://krazatchu.ca/wp-content/uploads/2012/01/hsv-rgb.jpg ) has weird nonlinearities (green is much, much wider than yellow, for example) compared to the Munsell color space ( http://upload.wikimedia.org/wikipedia/commons/e/e2/MunsellCo... ) which was experimentally derived from experiments on humans.
HSV is ok for color pickers where a human is picking a color, but it makes no sense when you are picking the H angle and generating color based on it, because a constant H angle delta does not correspond to a constant change in human perception at different base angles. In other words, if you have a base color at some X degress of H, and two accent colors at X+30 and X-30, you won't perceive the two accents as being the same distance from the base, X, because different H angles are perceived as different color distances at different points in the spectrum. The transformation from H to perception space is not linear.
And that's just hue. L, S, and V (pick two!) have their own issues, with different hues being perceived as different lightness or saturation at the same L or S value.
(Sorry for a late reply)