spectacular boarder or however you want to call it shouldn't have different colors.
You could give each rank 1 individual color but this shiny colorfull boarder should be exlusive for the legendary members.

The Legendary member rank should be kept special in it's design. Meaning It should stay the only one with more than 1 color.
Or else it wouldn't be special anymore.

At all I don't mind new ranks, I don't think It's a bad idea.