The male House Sparrow has a black bill in the breeding season and in summer.
In winter the male's bill is lighter in color.
Young males have a yellowish bill.
Females have a yellowish bill all year round.

1st photo: A male & female. Peaks Island, Maine, USA, 31 July 2015
2nd, 3rd & 4th photo: A male. Gilsland Farm Audubon Center, Falmouth, Maine, USA, 7 August 2017