I am growing out four BG's that are now 2.5"ish TL. Three of them have gone dark and the fourth is lighter just like the ones in your pic. Not sure why there is color difference.
Sent from my SAMSUNG-SGH-I747 using MonsterAquariaNetwork App
Im leaning towards female but thats my opinion alot of times they are darker.. it can be tricky ever try venting it..i shared some pictures of my geno types..