I wanted to share this site, ColorMatch 5k because it's one I use quite often. It takes the guesswork out of finding a color scheme, by using algorithms based on color theory to generate a color scheme based on your initial color choice.

When used in conjunction with EasyRGB.com which provides resources for color matching, harmonies, tint, monitor calibration, system colors, and color/conversion calculators you have a powerful, professional tool...and even better...free.