Source: Color Wheel, Fair Use http://classicshades.com/articles-colorwheel Photo of Josef Albers, Fair Use Simultaneous Contrast, Fair Use http://www.tumblr.com/tagged/simultaneous-contrast
Two hues which sit directly opposite each other on the color wheel.
A combination of three colors, consisting of a main hue and the two hues that sit on either side of its complement on the color wheel.
Hues which are next to each other on the color wheel; analogous colors on one side of the color wheel are considered warm and on the other, cool.
The effect two neighboring colors have on one another; this effect is contained in one of Albers' laws of interaction.
American artist, teacher and author of the "Interaction of Color"; he wrote one of the most important books on perception and the study of color theory.