I think they're both mixed breed cockerels. I also think they're much younger than 15 weeks.
The second bird is absolutely male. You can see saddle and hackle feathers coming in.
Since they're not pure, you can't sex by color. And the one being male but not having hardly any comb yet tells me they're younger.
If you bought females, you need to give the seller a chance to make it right for you.