Sounds like bile to me! Has he eaten anything new? My friends dog had the same problem just a week ago and it was caused by a new treat she had eaten. The vomit is yellow because there isn't anything in the tummy! I know that you can give them childrens mylanta or Peptol. The plain clear pedialite (childrens drink) is good too, the electrolytes keep them from getting dehydrated, kind of like gatorade for a human! Sounds like an irritated tummy to me.....but I'm not a Dr. Hope your baby feels better soon!
