I have (3) 5 1/2 week old red silkie chicks. One of the 3 hatched 2 days later than the other two (not sure which anymore). I noticed over the past few days that the combs on two of the chicks are turning from black to pink. Is this an indication that they will be males? Wasn't sure if both genders turn pink or not......or if the one without a color changing comb was just behind a few days....maybe it's the late hatcher?