I saw Sacrifice16's gorgeous colourisation tut but since I use GIMP I can't follow it.
So I made a version for gimp, uses fill layers, colour bal and hue/saturation
I used this pic of Jensen and desaturated it to make it black and White
the next thing I did was add a fill layer using #f2bc67. I set that to soft light and erased it from any area that is not skin coloured (the hair, the shirt, the eyes.).
Then, merge the layers together and go to colour- hue-saturation. alter the hue to -15 and the saturation to 10.
Next go to colour balance and adjust the midtones to 2, 7, -5. Finally for that layer go to colour- auto- white bal. it now should look like this
The next thing we are going to do is colour the lips. On a new layer, use a soft round paintbrush and go over the lips with #741a1a and set to soft light 50%
Onto the eyes. Remember Saiyuki's awesome eye enhancer
tut? Well that's going to come in very handy here as it's what i still use to enhance eye colour. Firstly on a new layer brush over the eyes with #92af4d and set to soft light 100%.
then merge the layers together. I then used Sai's tut to play around with the colours of the eyes until they looked natural.
Then I coloured the hair, on a new layer brush over the hair with #826938 and set to soft light 100%. I then did the same with the shirt using #385e82 and once again set to soft light.
Now we're in the final stages. Merge the layers together again and alter the input levels to 5, 0.91, 255 just to darken it a little.
The I went to colour- hue/saturation once more and played with the saturations. This time I selected the red/yellow and cyan parts at the top and set them to red- 10, yellow- 2 and cyan 3
Finally I sharpened it
this is the finished picture
and finally my layers panel