Colorizing Black and White

Here are a couple of works I have done colorizing old black and whites. As with many things I discover while using Photoshop, the most essential skill is with Selection and Layering tools. The more precise the selection them the better the colors will look. My first attempt was coloring an old black and white of Albert Einstein. There aren't that many elements so it was a good candidate.

Here I simply used Quick Edit Mode with additive selection and a hard-edge rounded brush to select the skin, the sweater and hair. Using the same method I did Abraham Lincoln.
The next one I did was of a guy wearing a striped suit. This was a bit more intricate so I used a small square brush and zoomed in selecting the dark areas.