Does she have other symptoms? Is her digestion going good? Is poop looks like a gel or transparent?
Food sometimes interferes in the color of the food, and do a proper observation.
Observe for urine color also.
Next Steps
wait for a few days or you can consult immediately if she develops other symptoms.
Health Tips
if you have a doubt you can stop milk for a few days and check whether the poop is changing its color or not.