Questions about my Swedish Ducks

[AmberH]

If we're judging by bill color, then there are two females and two males. The males would be on both ends of the front row and the two females would be in the middle. A black and blue of each color.

Thanks for all the input. The thing that still throws me off is that the light blue bird has a very green bill but yells like a female. The black with little white on chest has a blue bill but has a raspy whisper. I don't know... lol