It's possible that the two who are starting to "pink up" are still girls, just getting ready to lay!
Are they hatchery BRs? Or heritage BRs from a reputable breeder? The hatchery BRs will start to lay earlier than the heritage BRs because they've been bred for production over type.
I can't give you a definitive answer without pictures, but there is still a good chance that they are female.
How pink are the combs? Bright red, or dark pink? Or still a lighter pink?
You can also look at the saddle feathers, and see if any are starting to curve downwards. Here's a pic of my BR roo at about 15 weeks. Note the bright red comb and the curved saddle feathers.
