Red, yellow and blue :: In traditional color theory, these are the 3 pigment colors that can not be mixed or formed by any combination of other colors. All other colors are derived from these 3 hues
Orange, green and violet :: Colors created by a mixture of two primaries.
Red-orange, yellow-orange, yellow-green, blue-green, blue-violet and red-violet :: Colors created by a mixture of primary and secondary hues.
Colors located opposite each other on a color wheel.
Colors located close together on a color wheel.