I'm pretty sure the game comes with historical logos for every team and year. But if you're looking for something additional here are a couple of links that might help:
https://forums.ootpdevelopments.com/...highlight=1901
https://forums.ootpdevelopments.com/...31#post3423501
Also, in-game, Add-On Central may have what you're looking for. Or Steam Workshop, if you own the game through Steam.
Doing an advanced search in the forum might help as well.
With all that said, a white outline around logos tends to be a common thing. It's usually put there to help the logo stand out no matter the background. Some like it, some don't.