Now duplicate the image. Go to Layers>duplicate layer and press 'ok' when the text box appears.
In the layers pallette set the blending to 'soft light'
Go to Layer > New Fill Layer > Solid Color and select a 'dark blue'.
It should now look like this.
Now go to Layer > New Adjustment Layer > Levels and slide the black slider to the right a little, just enough to increase the intensity but not too much that you start losing detail.