They have a hundred different "poops" that are normal. How does the vent area look? Keep an eye on that especially with having the pasty butts. If it gets red or starts loosing down back there, then you have a problem. Yellow foam sounds a bit diahrreaish to me. I want to say they one I lost had yellow foamy poop. You can get sav a chick probiotic to put in the water that is supposed to help with the digestive stuff. For now I would keep an eye on the butt. If teh vent is staying clear and the down is staying fluffy, I wouldn't get too worried.Chips poop is like a yellow foam, is this normal? How is everyone doing?
I have a "poop guide" bookmarked. It's not so much help for the little ones, but if you want it to keep track as they get older let me know and I'll float you the link.