The influence of substrate brightness, contrast, and color on oviposition was quantified under noturnal light levels in choice tests using caged Anopheles gambiae for both wild and laboratory populations. Egg output increased as darkness of substrate increased against a white background. Black substrates elicited the most oviposition while white substrates elicited the least. Contrast of ovipositional dishes against the background also strongly influenced outcomes. The most eggs were laid on wet black substrates displayed on a white background. Very few eggs were laid on wet white substrates against a black background. We conclude that contrast guides females to prospective ovipositional sites; but, wet and dark substrates release the most egg deposition. No evidence was found for wavelength discrimination.