How do i get the purple pro badge?
You can find the details here:
Multi-color label
This more exclusive label is meant to distinguish the highest tier players who are currently active. The multi-color label can’t be requested; players who already have the Pro label and earned a Tier 2 or Tier 1 individeal achievement in the last year will automatically get it in their profiles. At the same time, it is automatically removed if a year passes since the last T2+ achievement was earned.