How does the four happy bird divide the father and mother

The four happy birds divide the mother -in -law mainly look at the hair color.Gong's covering feathers from the top to the tail are all black, with blue metal luster. The flying feathers and large cover feathers are dark brown. The flying feathers on the inner side are white, and the lower chest and lower tail covering feathers are pure white.The mother and the public are similar, but the black parts of the male bird are mostly gray or brown on the mother bird. The color of the flying feathers and tail feathers is lighter.