I'm usually NOT big on the whole online color scheme website craze.
But there is one website that I think certainly is up there in terms of overall being useful when it comes to using it in conjunction with web design or other programs.
It's called, '4096 Color Wheel' and it allows you to pick amazing colors on the fly.

Not only that, it gives you plenty of color scheme scenarios to figure things out.
It's pretty good. It's almost as if it is a color program launched on your computer, almost too hard to believe it is online.
Try it out.
http://www.ficml.org/jemimap/style/color/wheel.html