My Lab a purebred

Question
I bought Brucer My Labrador retriever he came with papers. when I met the owner of the dog he seemed pretty suspicious cus when I asked to see the parents he said ya that is fine but implied it was really far so if I wanted to go out I could I said no that is ok. I said I still want the dog I just want to know what type a dog I am getting.He told me he would send pics via e-mail never received. well he has a white spot on his chest pretty small and a few white hairs strayed a little on his tail. but a distinct thing I noticed was on his tongue there were two purple spots left and right on sides of tongue, does this mean he has chow in him?

Answer
A white spot on the chest and some random white hairs, as well as spots on the tongue do NOT mean the dog is mixed with any other breed.  

If you go to the AKC site and read the lab standard, it says that a white spot is permissable, so that means it's actually pretty common.

Regarding the tongue, I thought you might like to see this:  http://www.woodhavenlabs.com/tonguespots.html