true that you can not tell gender by spur bumps or spurs as some hens even get spursThat's not always true. I have had several hens grow spurs.
ETA: OP, none of your birds appear to have spurs, which is even curiouser, because if that red bird was a 2-year-old (or older) roo, he should have at least some spurs starting in...
not true i have a game rooster with no spurs at all.