I always assume Cleveland was a poop joke
In June 1945, a committee selected "Panthers" as the new team's name. Arthur McBride, however, changed it to the Browns two months later, the result of another naming contest that suggested Browns, not after Paul Brown himself, but as a shortened version of Brown Bombers, a reference to the nickname of boxer Joe Louis.
America's white press began promoting Louis' image in the context of the era's racism; nicknames they created included the "Mahogany Mauler", "Chocolate Chopper", "Coffee-Colored KO King", "Safari Sandman", and one that stuck: "The Brown Bomber".