He could be pure bred and field bred. Field bred dogs tend not to fit the standard but they are pure bred nevertheless. His colour would be called the kind of permissable yellow that is called Fox Red in Labs, I think.
A small white spot on the chest is permitted and white bits on the toes are not uncommon and are called bolo spots. Bolo was the name of one of the first purebred dogs way, way back who is thought to have introduced them to the breed.
Without a pedigree there is no way to tell for sure but he sure looks like a lot of pure bred Labs in my field training group. Wow, look at the muscles in his backend. Maybe he's going to need lots of exercise to keep that kind of physique up? Lots of fun ahead for you. Nice boy.