Adult males are bright blue on top and on the throat with an orange breast and sides, a brownish patch on back, and a gray belly and undertail coverts. Adult females have a duller blue body, wings, and tail than the male, a gray throat, dull orange breast, and a gray belly and undertail coverts. Immature Western Bluebirds have duller colors than the adults, they also have spots on their chest and back.
They are sometimes confused with other bluebirds, however they can be distinguished without difficulty. The Western Bluebird has a blue (male) or gray (female) throat, the Eastern Bluebird has an orange throat, and the Mountain Bluebird lacks orange color anywhere on its body.