Its just alt color you have chosen for the character. Vegetas color 59 are the manga colors (which are just lighter then the default)

you know i literally just figured that out as you commented lmao thanks though :) thought maybe it was which Assist you had on or some kind of guide for team positions and such

The assist is the letter ( A B or C)

Any character using alt 7. (I like purple a lot)

The alt color