Most of the colors are, but not all of them. Plus, some people are confused about what a 'bib' actually is. The wilds, redbreasts, cinnamons, and golden pearl males all get bibs, and as far as I know the females don't. Silver males get bibs, and sometimes silver females do too.
But I remember a post not too long ago that had a red-breasted female that the owner thought was bibbed because she had a 'clear' blond area below her chin that they mistook for a bib. That's why I always correct when someone says that 'bibs' are a sexing tool. Bluefaced males don't get bibs, so if the bib was a way to sex buttons then I guess all bluefaces are female, even if they don't lay eggs
ETA: as far as having groups of males, I think that depends on the birds. I've got some that have been together their entire lives and don't have any troubles with the males fighting. Mine have been in colonies, though I'm slowly thinning my extra males out. One pen I had at one time had 4 females and 5 males, but due to too-close breedings all the females died around 1 year old. Those males all lived together for months without any fighting, and have since moved on to greener pastures somewhere in Texas