Welcome to YT! There will be no difference between a standard yorkie and a part carrier. A parti carrier will look exactly like a "regular" yorkie.
He will carry the pie bald gene that gives the tri colored look but it won't be expressed. Some standard yorkie puppies can have a little white on their chest, but that doesn't make any difference, they end up with a more standard coat anyway. If you want a tri colored yorkie, you need to find a pup with two pie bald genes, in other words you need to find a full parti.