Another aspect of complementary colors is that they are each other's afterimages. This has been used to great effect by syncretist artists, as well as
in one of Jasper Johns' Flag paintings. It consists of a flag painted in green and orange, with a white field the same size above it. Stare at the flag, then look quickly at the white field --

You will see The Star Spangled Banner in Red, White, and Blue.