Coloring 2d hair

Okay, Im starting with a base image from my dA gallery, since Im exceedingly lazy and didnt want to do new inks for this. Prep your image however you normally would for coloring. I set my inks layer to Multiply and create a new layer for the color.

Image 1: Basic fill of background color. Pick something about halfway between what you plan for highlights and shadows. Im going with a rich brown, with a tad of red in it. Fill the hair however you like, so long as its solid. I usually use the Pens/Flat Color tool in Painter. Use the fill bucket if you like, but make sure you go back and fill any bits it misses.

Image 2: Highlights. Choose a color a bit lighter, and a bit less saturated than your base color. Using a slightly smaller brush size, go over your base color in areas you want highlights. I usually stick to the middle of wide areas, and avoid the roots and tips of the hair, as those will be shadowed later. Also, try to follow the basic curves of the hair. If the hair curves, so should your highlights. Remember, once you've done your shadowing, you can always come back and add a few more highlights if you think they're needed.

Image 3: Shadows. I tend to go with a color a bit darker and with more saturation for shadows. Fill in the roots (even natural hair has darker roots where the sun hasnt lightened it yet), tips, and anywhere you want a bit more texture. As a side note, I usually use the shadow color for the eyebrows, as eyebrows are normally a shade or so darker than natural hair color.

Image 4: Blending. I love the Blenders/Just Add Water tool in Painter, but you can probably use your favorite blending tool just as well. Blend from the middle of the highlight or shadow outwards, in the direction the hair is flowing. As I blend, I add a few more highlights and shadows where needed, since some detail is lost in blending.

And there you have it. My current hair coloring formula. I arrived at this process through trial, error, more error, and more trial. Have fun with it.