Yay!! I get to nit-pick before Faldage does!!

Jazz points out:
they're also called complimentary colors because they go so well together.

Close, but no cigar. Pairs comprising one primary and one secondary (made from two primaries) color are called 'complEmentary" because, opposite each other on the color wheel, when taken together they encompass the entire spectrum, or white (light)/black (pigment). [/thus endeth the picking of the nits]