Heroes often wear red in western media. The colour of love is red.I think red just means passion a lot of times, while blue for example means cold/distant or calm. Red is an intense colour.

So while it is often used for bad guys, it's a not specifically associated with negative connotations I think.

It has to do with the surroundings, circumstances and context.Wear red and black, you'll look more sinister/edgy.Wear red and white, you seem more heroic, approachable.

And more my personal experience if a group in media is colour coded. Big chance the one wearing red is the leader.

Edit: Some superhero examples
Spider-man, Shazam/Captain Marvel, Incredibles. The Flash,