The HSV model is easy to use if you want to address colors of the HSV-color wheel, like rainbow effects. You can simplify the conversation by setting value and saturation to fixed value (normally 1). The bad thing in doing this is, that you reduce the possible 16,7 mio colors to 256 colors, what is still good enough for the most effects. The good thing is, that you only have to deal with one value : "hue" to represent all needed colors.
To address colors directly I agree that it's better to use the RGB model.
For the next project I will give the integer calculations a try. But for now I can live with the solution I have, cause the orb is a birthday present and time is not my "friend" at the moment :), cause there are still some mechanical problems to solve to make it a "good" present.