Color Palette Editor includes a number of default schemes.

AnalogousAnalogous color schemes use colors that are next to each other on the color wheel.
ComplementaryA color on the opposite side of the wheel from the source
HarmoniousA variation of analogous where a color is taken from each "spoke" around the wheel
MonochromaticVariations of the same hue, with evenly spaced saturation stepping
Split-ComplimentaryThe split-complementary color scheme is a variation of the complementary color scheme. In addition to the base color, it uses the two colors adjacent to its complement.
SquareThe square color scheme uses four colors arranged into complementary pairs spaced evenly around the color wheel.
TetradicThe rectangle or tetradic color scheme uses four colors arranged into two complementary pairs.
TriadicA triadic color scheme uses colors that are evenly spaced around the color wheel.