Which arrived just after the nick of time.
Complementary colors are a convention of artistic color theory (like scales being a convention of musical theory; in the sense of theory as a set of related ideas, not scientific ones).
A warm color is paired with a cool color opposite on a color wheel. Colors selected are used for differentiation, directing the focus of attention, as well as inducing a particular feeling in the viewer. (See my examples above.)
It is not functionally the same as color picking for accurate color reproduction.