What a pretty creation. the colors you paired with the purple work great and you accomplished making a purple quilt with style. I agree with MadQuilter on the border.
If you have to make it bigger for size, I would add another row of blocks if you have enough fabric rather than a small border.
If you want to add a border for the effect, make it a wider than average one to give it some omph. Figure out how much fabric you have to work with and make the border as wide as it allows.
peace