In the world of birds if there is a difference in color between male and female it is typically the male of the species that is brighter and more colorful. The reason for this can be that the more colorful males are more appealing to females and thus more easily attract a mate, thus ensuring that their more colorful DNA is passed down. Or if the species typically nests in a more vulnerable location, such as the ground, females that can blend in better are more likely to survive, along with their eggs. Since the males do not spend much time at the nest they do not need the same camouflage
The Wilson's phalarope is just the opposite of most birds. In this species it is the female that is more colorful. This is to be expected because it is the female that does the work of attracting a mate. So it is important that she look pretty. The male's dull plumage is also an advantage as he is the one that stays home to take care of the little ones. The female lays her eggs in a scrape in the dirt and then takes off to find a new man, leaving Mr Mom to build a nest of vegetation around the eggs. With sole custody he will raise the young on his own.