Similarly, your brain interprets blue objects as being farther away than they actually are. Artists make use of these effects in their work. Blue sky, mountains or seas are used to give depth to a painting. An observer's lens becomes thinner when viewing blue objects. The lens is getting thinner, so the object is farther away.
Artists use reds, oranges and yellows to make objects stand out.
The viewer's lenses have to thicken slightly to bring these colors to focus, and the brain interprets the thicker lens to mean the objects are closer.