In the silver color I have a male he has a bib My newer silver babies I don't believe will. Are they female or could they be either sex in the solid silver no bib
how old are they? If they are less then 6-8 weeks then it is going to be hard to tell just from color. You can judge be the way they act and if they call/crow as well as the full adult feathers are somewhat different. You could post photos and we can help from them. It does sound like females but with silvers it is hard to tell.
wow from these photos it is too soon to tell. they don't even have full feathers on the chest yet. Give it a couple more weeks then you should be able to tell. good luck