What a pretty mini..lovely color combo... I would use just the purple border and also purple in the binding. I'm trying to envision a white border or flange, but think that's what you will see first, not the undulating shades of purple/turquoise. Since you have the purple already on, audition a white flange with a piece of white yarn placed where the fabric would be. Then stand back or take a picture, and ask if you like it.