Not sure how old your puppy is, but 12 hours is quite a long time for a pup to go without food & gastric juices could spark a secretion of bile to be vomited.
My pup was a bit sickly when I first got her...so had to feed her meals throughout the day, rather than 3 times which I'd usually do at her age.

Is bile dark brown and thick?
He gets his last meal at 6pm. Breakfast at 6.30am.

How old is your puppy? If he is still a baby then he should be having a meal for supper, even if it's just a couple of biscuits at bedtime.

I do hope he's going to be ok.

He seems fine.

He is 17 weeks old and has three meals a day.

No, bile will always be bright yellow. The frothy white stuff is from an empty stomach though.

Yes, I also think that's too long from 6pm the following evening. Your puppy should get something, a few mini markies, a couple of gravy bones, something, at bedtime.

How has he been since that sick this morning??

Are you doing a regular worming programme, it's quite imperative when they're puppies? There is a regime you can stick to, which obviously your breeder will have done some of, then I think you take over at 8, 10 and 12 weeks old, did you do all that? I'm still harping on worms here that's all sorry!