This tutorial didn't work so well because in the middle of it, a jpg. file of a photograph that was needed to use to create the light reflection was a faulty link, but here is how I got this far on trying to create coloured lighting on Photoshop.
1. I opened the photograph I wanted to use and using the pen tool I cut around my model and with her selected, I pressed Ctrl and clicked on the layer to rasterize it.
2. I selected it with the magic wand tool and pasted it into a new layer. I also deleted the original layer with the background.
3. I created a new layer and filled it a light blue colour with the paint bucket tool, I named it light blue background.
4. I created another new layer and using the gradient tool I used a linear gradient with a bright orange and vivid pink colour, I changed th elayer mode to screen and opacity to 100%.
5. I duplicated the orange/pink layer and I added a lens flare effect to the top right hand corner of the picture and on the settings box of the flare I set it to movie prime at 184%. I changed the layer mode to hard light.
6. I went to the brush tool and I chose a dimater of 345 on a soft looking brush and made some orange marks above the models head. I named this layer orange brush and duplicated it.
7. I created a new layer and repeated the paint process from step 6 but with a bright pink brush making some spray marks behind the models neck, I set the layer mode to screen.
8. I then used a large (about 500 pixels diameter) soft white brush, opacity of 20% and carefully sprayed the right hand side of the model slowly bringing up the colour.
9. Above the model layer I created a new colour balance adjustment layer and inverted the mask selection to make it black. I set the midtones to R = -52, G = 75, B = -49.
10. I clicked on the mask again and slowly marked out a few areas around the models face and arms with a soft brush.
11. I created another colour balance adjustment layer with the midtones set to R = -43, G = -55, B = 100. This time I used a slightly harder brush in the same areas of the mask as I did before.
12. To add more depth to the colour range, I added a hue/saturation adjustment layer below the model layer, I ticked the colourise box (hue 22, saturation 42, lightness -20).
13. I then added a duplicate layer of the model one and sized it up 200%, I added a layer mask on this and masked out unwanted areas that would overlap my original model.
14. I duplicated the last layer I created and gaussian blur on it and set the layer mode to screen. I placed this layer and the last layer above the white brush layer I created earlier.
15. I created another brush layer above te colour balance adjustment layers and repeated steps 6 and 7 gently spraying the arms.
16. I changed the layer mode to hard light. I repeated this with a bright orange brush layer and changed it to screen mode.
17. I created a hue/saturation level and repeated what I did before in step 12, I changed the settings to hue 218, saturation 83, lightness 0 with the colourise box ticked.
18. With a medium sized brush set to 30% opacity I masked out some areas and inverted the mask.
I thought this result was too bright for my dark looking photograph that was mainly black and white. I didn't enjoy doing it either because of how lengthy it was and the fact it wasn't worth it because I couldn't finish it.