I've also did handle my background too, using only 2 tones basically - the blue and the pink.
Now it is time to adjust the colors - I really can't imagine working without color adjustments. Create a new layer and drop a gradient on it. The gradient top color is something like image background. Click to find out the best layer blending mode
Create another gradient along with a new layer.
The same thing with the lower part - the same technique was used there.
A little bit of color adjustments:
And this is basically it. This is hard to explain by words- you should always find the perfect value definition. Like in this part of the image:
Try not to spoil such details. See you next time.