Blue Fawns "can" breed true, BUT that all depends on what other colors have been introduced into the line.
Blue Fawns can also come from Greys. Only if someone has introduced Blue Fawn into their lines somewhere.
I see a Snowy female, Black Bibbed Male, Blue Fawn Male, and a Grey Male.
I hope you plan on getting more females soon or taking 2 of the males out since the 3 males will end up killing the female from trying to breed her.