Underside of Immature Bed Bug
Bed bugs are known to have color vision. The best evidence is a study by a group of scientists* who studied orientation to shapes and colors Bed bugs orient to black or red objects in preference to white or other colored objects. Bed bugs prefer vertical objects to horizontal ones.
The test arenas, bed bugs do not distinguish black and red. This has been confirmed by a study of the bed bug genome. The bed bug genome contains two opsin genes, one sensitive…
Source: Living With Insects Blog