Hi Rachielou,
How much of the flower fabric do you have? I would suggest using a darker fabric such as the flowers or something similiar to it and/or something similar to the other dark print and make a flange fabric accent border or a medium size piping border between the purple and the outside border. You can then also add another border on the outside if you need it to be larger. If you find other fabric, lay them out and take pictures we'll help give you our opinions. I hope all of that made sense.
It's looking good so far. It's hard sometimes to see the colors in the pictures online.
Pam M