Plumage color aberrations in wild birds are infrequently reported and often misinterpreted. We report a color aberration in the Gray-headed Swamphen (Porphyrio poliocephalus), a large colorful rail with a red bill and a frontal shield. Our report documents the observation of a diluted plumage in an adult Gray-headed Swamphen for the first time. The bird displayed an almost all-white plumage with normal-colored eyes that we assigned to a dilution process. We also summarize plumage color aberrations reported in 3 additional species of the genus Porphyrio.