I’m sure you have seen photos that have been hand coloured when a photo restoration has been made. They might be the old photos you own or photos you have seen on the net, coloured by “restoration artists”. Old photos were often tinted with inks, this post is about digital colourization or hand colouring using a computer. Firstly there are many ways to add skin tone and tint photos, this post just describes one of them. Perhaps you have never seen it done this way before but this is good for toning skin and lower resolution images where other techniques may not be appropriate. We start with a black and white image, its best one with a good tonal range, for the colour to “stick”. Images with hardly any shades of grey are difficult to tone. There needs to be some texture and tone to colour. Here is a small image showing 3 tones of grey “coloured” (an overlay layer set to colour) with the same shade of skin. Using an overlay layer set to “colour” in the blending mode options dropdown is the basic way to add colour to an image.
How colour modes affect a grey tone
You can see how the colour is denser on the darker shade or grey. The lighter shade of grey takes on just a touch of colour. If the image you are trying to add colour to, needs to have a darker skin tone but the shades of grey are very light then it will be tricky to achieve this using the “colour” alone. We can use the below technique to darken the shade. Using the same colour tint as above and
How blending colour modes affect a grey tone
by using different blending modes the colour tone can be darkened to affect the image in different ways. Sometimes when toning an image it is not obvious which of these will give the best results, so it’s best to try variations and also to vary the opacity slider on the overlay to alter the effect the overlay mode has on the image. You can see that “linear burn” has the greatest effect here, giving the darkest or most saturated tone. Let’s try this with texture and see how it affects a multi-tone image. 
How colour blending modes affect a multi-tone image I have used the same colour tint and changed the blending modes or each overlay layer to show how each mode affects the underlying image. With this knowledge, it is possible to use these modes to make the colour “stick” to the image to make a convincing colour tint. When you introduce some texture into the equation you will find that this changes the way the overlaid colour looks. It will not be the same as on plain tone grey.
How texture affects the colour
To obtain convincing skin colour tones from the internet just search for “DeviantNep” who gets credit here for some super swatches and colours for creating skin tones. In part 2 colourising or tinting an old photo tutorial I will cover the process of actually tinting the photo. If you wish to see all the other techniques involved in colouring see colouring a black and white photo.
Very useful information. This is something I often get asked to do but with my limited touch up abilities it is something I struggle with. Your post has helped me considerable. I will certainly be trying this out in future. Good post.
Why don’t you have a site on the basics of fixing creased or otherwise damaged photos in black and white – without adding color. Old photos have a charm of their own and colorizing the photos takes away from the antique feeling of the photos.
Through out my blog there are posts on techniques used for fixing old and creased photos. You just have to read them and find them. They are there! Have fun!