I have to agree on the Manchurian Gold in Picture # 3. Don't see any speckles on his chest. Well maybe Reddish (Male color) speckles starting. In the first picture I assume the other one (I assume it is different from Picture 3) standing tall is also a male. No Dark Speckles on chest = Male. You may have a dominant male and a more submissive male on the M Golds.
Good luck with the Rosettas.
edited to add: Why are you holding out on taking an individual of the one in front of the feeder in the first pic. Can I see a close up. I think I like that color but I can't see it very well. Go ahead make us drool.
My coturnix chicks have been tame since day one. I can just reach in and scoop them up. I'm able to move them from one Rubbermaid to another while cleaning their cage without them making a big deal of it. The only time they go nuts is if they see FOOD coming their way...
It's the time of year. They are taking longer to mature, I notice.
I have 7 week olds - a few are roaring to mate others are: huh, you think I should do what? No way, not even interested.
So, now I have a few that are a week old in the brooder and I may have to wait till Spring to beer test them. Excuse me, wine test them.
Vent sexing would be knowing for sure and there is no fun in that.