Sometimes, I like to experiment with adding color to my drawings with a computer.
These rosebuds were drawn with graphite pencil and then colorized using Photoshop. I usually use Photoshop to do this but Painter works well too.
I just scan a drawing, bring it into the program, create a new layer and set it to “Color,” and then add some color to a portion of the drawing with a brush. I usually create a separate layer for each color I add.
The colors in the default pallet are usually too intense, so I adjust each one by “fading” its intensity with the “Opacity” slider. If fading doesn’t give me a color I can live with, I adjust it from the Image>Adjustments>Variations menu where I can change the hue and value.