Thought I'd have another go but this time with the dark hair/ purplish colour scheme.
I changed the hair using a Gradient Map adjustment layer, and used a Colour layer to change the blue light to a purple and pasted in the original greyscale at low opacitiy to bring back some details that had been lost in the glow.
Also having been super-impressed with Banj's image and the way it had a lovely more unified mood to the colour I tried improve the lighting consistency using another Gradient Map on top that went from a bright purple to a dark blue and then to black.
When colouring greyscales there's often a danger of getting a "Colouring-In" look with far too much local colour and the final Gradient Map can really help with that by giving it the whole image unified ambient lighting.
Also I noticed that by switching to darker hair I lost that lovely silhouette that you'd created for the character so after failing with a bit of rim light I instead put a bit of a dull glow in the background to make the top of the head pop back into view.
Oh and now that I'm back on my PC I'll try and post the link to that video I mentioned before.