Two colors directly across from one another on the wheel are called complementaries . Complementaries, or opposites, like red and green, strongly disagree. When placed together in a work of art, opposites create visual tension. Two agreeable color schemes are analogous and split complementaries. Split complementaries are three colors on the wheel in which one color is teamed up with the colors on either side of its opposite, or complement.
Analogous colors are three neighbors on the color wheel, like green, blue-green, and blue.
Another common way to classify the colors on the wheel is by temperature. Look at the paintings by Vincent van Gogh on pages 70 and 71. One is warm, the other is cool. For this course, you are not expected to memorize the color wheel or terms that are not listed at the end of the lesson. If you would like to know more, go to this site on exploring color .