While this isn't the 1950s, this happened.
Back in the 40s, a comic character named
Captain Marvel appeared in a series called Whiz Comics (issue 2 to be exact). The guy wore an all red outfit with a yellow lightning bolt on his chest. The character was actually a 12 year old boy named Billy Batson that worked as a news announcer for a radio station. When he said SHAZAM! became Captain Marvel. He was a human, born on Earth, given his powers by an old wizard (Shazam), and had no laser eyes but only strength, speed, flight, blah blah.
The comic character became so popular, because it appealed to kids. It wasn't a kiddie comic like only kids read it, but teenagers, etc enjoyed it because here is this boy, around there age, playing super hero, what every kid wanted to be.
DC comics got pissed. The comic was so popular it was out selling Batman, Superman, etc.
So they sued the people who made Captain Marvel, claiming it was based off Superman. The 2 bare little resemblance to each other in both costumes and looks. Both are musclar, have red on there outfits and dark hair, but the colors are completely different. After all, Marvel doesn't have blue on. And Superman doesn't have white on.
DC Comics eventually won the lawsuit and acquired the legal rights to Captain Marvel and now Captain Marvel is a DC character.
The moral is, even if they are totally different, if there is any similarity, the more powerful can win. While Captain Marvel sold more than the most popular DC comic, DC was still king cause they produced a dozen others that out did Marvel.
I can't think of anything to put here right now.