Color wheel with other color modes
Similar to what MODO has for their color wheel. SO USEFUL to see complimentary colors, Analogous colors. you can really add a lot to your textures by seeing these colors defined.
Since you are making a new one or improving the actual colour wheel and slider I propose to take a look to my Color wheel proposal:
That allowed in a simple way to change colour and where sliders are aligned with the colour. The idea is that the vertical slider on side controls the luminosity and horizontal on the bottom or top controll the saturation.
Will be available in the Unity asset store but just the image by itself can help you to have an idea or impresion.