This is just my opinion (but it's your quilt).
I would have made the purple border 4"-5" wide (or even wider - I love wiiiiidddddddeeee borders!), bound it in the same fabric, and called it a day.
The thicker border width would have really solidly framed the quilt, and the inside blocks would just pop off it.
The inside is so interesting with all those lights flickering that putting the same fabrics so close on the outside takes away from it.