Sometimes I also have a hard time wiping all the poop off my baby's bottom, and there will be discoloration on her skin too. But it all comes out in the bath, so when plain ol' wipes won't cut it, I give her a quick bath.
Your cream could create absorbency problems with cloth dipes, though, and/or even making it harder to wipe her good and clean after a poop.
green poop is sometimes a sign of foremilk/hindmilk imbalance, but not always. If it looks greenish in the diaper, but yellow on the wipe, it's probably fine. As always, what matters is that baby is gaining and developing normally.