I'm creating an iOS game that allows the user to customize different parts of the main character with a color picker of three sliders. I'm wondering which would be better for the user experience, HSB or RGB? Have there been any user studies on this? I don't even know if it's a pressing issue that other people have asked but what is your preference on the idea? I'm leaning towards HSB because it seems to separate the different aspects of picking a color better.
HSB, because it adheres better to the 'natural' way people perceive color. RGB is a problem for most people. They don't get how to mix yellow from red and green, for instance.
That said, a color circle (H) with two sliders (S and B) may be better. But it takes up more space in the UI. Can you afford that?
Another option, which could make a lot of sense, is to limit the color options to a fixed set of colors. Because offering virtually limitless options could creates more problems than it solves.
I personally prefer selecting from a color wheel. One advantage of a color wheel is that you can leave markers from other color choices visible on the wheel itself. That way if I'm trying to come up with a complement, I can quickly look to the opposite side to pick the trim color. Or I can gauge if my three main color choices are about 120 degrees apart. You might even consider initially linking the primary and trim colors, making it even easier for the user to find a pleasantly complementing color.
I have also seen usable designs that use hexagonal tiles in a wheel shape, allowing the user to select from a discrete palette.
Another argument in favor of a wheel is that sliders and RGB or HSB numbers are a very "computeresque" experience, while a color wheel is a more human analog experience. iPhones are all about designing the interface for the humans.
If there's a different reason you insist on three sliders, why do you feel you have to limit the user to either HSB or RGB? I've seen plenty of applications that use a toggle to select the mode.