Guessing dogs breed?

[ILoveMyShelterBaby]

Hello! I am new to this website, so apologies if this is in the wrong area.

My boyfriend and I adopted a dog at the shelter the other day. He's the sweetest puppy ever! He is 5 months old, and they shelter guessed that he was a border collie and lab mix. I can see the border collie, but I'm not 100% on the lab part. I was just curious as to what others thought he might be. His coat is brindle, my cracked Iphone camera does not do this boy any justice!

This is the photo the shelter took of him:

 

[milos_mommy]

I'm not 100% positive on this, but I'm pretty sure if he's brindled, that means he needs to have someone in his ancestry that carries the brindle gene - so something other than border collie and lab, something like boxer, pit bull, mastiff, greyhound, etc.

Border collie wouldn't be my first guess, but it's possible! It might be easier to tell as the dog gets older. My guess would probably be golden retriever X pit bull, but that is a very very random guess - he'd need something with the long haired gene to get his coat, and his face has much more of a golden look to me than a BC, and although I don't really see pit bull traits, they're one of those most common shelter dogs and it could be where the brindle came from.

My best guess would be one or both of his parents were mixes of one or more breeds. He does have some really chocolate looking color, but I know nothing about color genetics, so I'm not sure if that might be indicative of chocolate lab in his ancestry? I think my most educated guess would be one parent was a chocolate lab X pit, and one was a golden or golden mix.