One of my mental hobbies is observing and analyzing sports “liveries” (mostly motorsports, but stick-and-ball team branding and uniforms often creep in too). This morning I happened upon this demonstration of unsolicited and unofficial NFL helmet redesigns that I though was interesting. The article writer offers some critique with each example, but I wouldn’t attest to any true added value there.
It’s worth mentioning that there is no “before” image accompanying these redesigns, so you’d have to already know, or look up, the existing designs to form a basis of comparison.
https://thesportsdrop.com/artist-reveals-absolutely-incredible-helmet-designs-for-all-32-nfl-teams/