Color scheme designer is probably one of the best color scheme choosing tools that I have come across (at least for color challenged me).
It has multiple color schemes to choose from, where if you want you just have to select one color and the others get set automatically based on the type of color scheme (mono, complementary, triad, etc.)
The other feature I really like is that it shows you the color scheme on a typical web-page design – making it even easier to figure if you like the color scheme or not.
The main color scheme chooser wheel.
An example web-page that uses the choose color scheme.