any clue for my breed?

[sir harley]

i adopted a dog suposed to be lab - rottweiler mix, but now he doesnt look anything like that. he just has the colors of a rottweiler but he looks like a terrier or a schnauzer or something else.
He is only 5 months and his weight is 40 pounds. he has really big paws and his colors have been changing since the first day that we got him. so do you have a clue of what breed he might be?

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