What breed of dog is pink?
Not a breed, but there are dog hair dyes, so:
Quiche La Poodle!
why not ''chłopak''?
should be ok too. If not report "Chłopak rysuje różowego psa." as correct
But as "chłopak" is teenager or young adult and "chłopiec" is usually a child, the child drawing a pink dog is more obvious than young adult.
while the pink dog breed is a west highland white terrier which was dyed pink