in wild-type drosophila (fruit flies), red-brown eye color results from the deposition of two pigment types in the eye. in each eye cell, red pigment is produced through the ommochrome pathway, and brown pigment is simultaneously produced through the drosopterin pathway. a transport system, made up of multiple transporter proteins, then shuttles these pigments to be deposited together in special areas (granules) in each eye cell.