What Breed is My Dog?

I got a Chihuahua off craigslist. I was told he is pure bred, but he looks a little old for 8 weeks. I was told it's possible he's mixed with German Shepherd. I am not allowed to have big dogs where I live, I really love him so I'm hoping he is just a Chihuahua so I can keep him. Please let me know what you think he could be mixed with.

He is brown, has black and white accent hairs and a strip of white behind his neck, one white paw and some other paws have white toes. The tip of his tail is white too. His face is colored like a German Shepherd.
Maybe they lied and he is a mix, I've never really seen a Chihuahua who is so multi accent colored.

By Kendra S.