This setting:
Settings shortcut: Theme management > Highlight color
It changes the color of some elements. Mainly the community names.
It’s nice to have the same settings for different profiles, but I set a different highlight colour to differentiate them.
But you can sign up to as many instances as you like with the same username and email.
But, like anywhere else, I would strongly suggest to use different passwords.
I only change TVs when they die. Mine is 12 years old.
And they didn’t even use “Brain Damage”.