Ehhh that's concerning lah, I'd really suggest you check with the pediatrician about this ASAP, maybe even balik ke hospital where dia kena fototerapi dulu because the darkening of lips after phototherapy isn't something standard that mums usually report. Bukan normal biasanya, so better safe than sorry, especially since it's a visible change on the baby's face. Jangan delay ye, better to get it checked out quickly than worry at home!