I think the colors have as much significance as you give them. A lot of times you'll see red and associate that with the top dancers, which some teams do intentionally, but that isn't always the case. Some teams I know (DRP my freshman year did this as well) randomize colors completely. I know a common thing to do here is assign top jodis a more vibrant color (teal/blue/red/yellow) for visibility. All situational imo
I would say it doesn't mean anything really but colors are a thing that create some implicit biases. Red is typically considered top Jodi and oddly I've had judges tell us to stop putting our better dancers in colors like light green and orange so we typically put at least one pair that is considered our better dancers in red. Personally I don't think "bottom" Jodi's should be in yellow or any equally bright color because bright colors just attracts so much attention. One thing I can tell you for sure though is that if you're on a black stage, you should put the bottom Jodi in black because that pair will completely blend in with the stage and it's much easier to hide that pair.
imo the ways that color comes into play really depends on the how cohesive the level of dancing is on a team. I’d think that a team of similar skill level would be more likely to take turns with vardi and assign them arbitrarily. Teams that lack cohesion in level of dancing may try to avoid giving newer dancers very bright colors in hopes that any mistakes or form errors will be less obvious.
But no matter what color you are, if you’re killing the set then you’re killing it - color is meaningless.