Bring those old pictures to life

Coloring a black and white Photo

Use the 'Retouch Tool' set to 'Color to target'

Choosing the colors.

Click on your Foreground color to open the Color Palette.
With this tool only the horizontal position of the marker is important.
If you have difficulty choosing skin tones you can open another photo which has what you want and click on it while the Color Palette is open.
It is then a simple matter of dragging the brush over the areas you need colored. This will not change the contrast so black will still be black and white white but all other tones will be colored.

In this case, right or wrong, I remembered the old "London & North Eastern Railway" sign boards being green.

One thing to remember when coloring black and white photos is to keep the colors muted (not too bright).