According to Chinese auntie folklore (not sure if science backs up this point):

• If the poop is yellow and clumpy, then the kiddo has eaten well enough in the last meal.
• If the poop is greenish, then that's a sign of poop getting oxidized (hmm?) in the gut (hmm?), i.e., it's been there for a longer than usual amount of time, and hasn't been moved through the bowel, so that's a hint that the kiddo hasn't eaten enough the last meal.