My 8 month old boy was playing with gel pen and his tongue is green..I immediately washed his tongue but greenish color is still there. what should I do

A. Dip a gauze- or cloth-covered finger into the warm water. Gently open your baby's mouth, and then lightly rub their tongue in a circular motion using the cloth or gauze. Softly rub your finger over your baby's gums and on the inside of their cheeks, too.