Okay so personally I was paranoid about this too when I was breastfeeding, pero from what I've read and asked our pedia, hair color should be fine as long as you're not ingesting it, the chemicals don't really get into your milk in significant amounts. That said, mag-check with your OB or pedia lang to be safe, especially if you're using stronger treatments, kasi every mama's situation is a bit different at mas comfortable ka na lang if you hear it straight from your doc, no?