Color Wheel
(ROYGBIV)
Complementary colors lie across the diameter on the color 
wheel
and combine
to form Òwhite lightÓ, so the color of a
compound seen by the eye is the complement of the
wheel
and combine
to form Òwhite lightÓ, so the color of a
compound seen by the eye is the complement of thecolor of
light absorbed by a colored compound; thus it completes the color.