Black and white dog

Question
My dog is mostly white and some black but somehow the hair on his belly and face is yellowish and i don't know why? Can you cut the hair out and the white hair will grow out or is it always like that with white dogs?

Answer
Start using a whitening shampoo.   The hair on his belly and face are more exposed to things like urine and saliva which can stain the fur.  It's next to impossible to get the staining to completely disappear but as the hair grows, if you continue using a whitening shampoo, you should see a significant difference.  If you cut the hair it would be white when it grown back but it could easily become stained again.