In general, the NFL has a rule for ever PR or appearance thing... how strongly said thing is or isn't enforced depends on if it's an owner or manager trying to do it...
But that's why players have called the NFL the No Fun League...
The NFL has started to loose up a bit, but really only after the George Floyd riots... and even then, only for selected things or select Sundays.
One NFL player wanted to wear pink shoes all year long, which the NFL allows for breast Cancer month, and said player's family had a long history or the women getting breast cancer... so he wanted to do it all season long... NFL forbid it and threaten to fine him if he kept it up.
Honestly, I don't see the issue, they were NFL approved shoes, made by the NFL's cleats sponsors, and the NFL allows players to wear pink cleats to support ... but I guess only NFL only support it one month a year...