Painting hair in watercolor calls for imagination and letting your creativity flow. This is the fun of the medium. You will want to give your subject's hair depth and interest, as well as variations in color. Never simply paint brown hair brown!
For this exercise, let's say you will be painting “brown” hair. First decide upon a light source to give the hair highlights which glow. There should be distinct areas of light and dark planned to provide contrast. Once the highlighted areas have been determined, outline them lightly in pencil. Focus on masses and their values at this point. (You will identify strands later when you are nearer completion.)
There are many browns which can be purchased in tubes, but I much prefer the ones I mix. This gives me the freedom to alter a color, ever so slightly, to just the shade I want. I feel these colors are far more interesting as well.
Before you begin painting, spritz the back of your watercolor paper with water. This will help to keep the paper from buckling. Now paint over all of the hair with Aureolin Yellow, and while this is still wet “drop in” some Rose Madder Genuine. Tip and tilt your watercolor paper allowing the two colors to mix together. Before this is dry, “drop in” some Viridian Green and a little Cobalt Blue to your mid tone and darkest sections. Again allow the paint to mix and run on the paper. This is fun! Try to keep your highlighted spaces covered mainly in Aureolin and Rose Madder Genuine, as this portion of the hair will shine as if in sunlight. Let this dry.
Mix some browns and set them aside. First combine Aureolin and Light Red, then add Viridian until you achieve a mid-tone brown. (mixture A) For a cooler brown, mix Aureolin with a small amount of Indian Red, then add Viridian. (mixture B) For your deepest brown, blend together Aureolin and Alizarin Crimson, then sprinkle in a small amount of Winsor Green. (mixture C) The Alizarin Crimson, and Winsor Green are staining colors and can't be completely “lifted” so use them carefully! They are however, transparent which keeps your painting vibrant, and reduces your chances of producing a muddy opaque brown. Hopefully you will have some purples, greens and blues by now.
Focus on those areas of hair you have designated as mid-tone and loosely paint there with your brown mixture A. As you paint, leave some of the Aureolin/Rose Madder Genuine you painted previously, showing. “Drop in” a little of your mixture B to your mixture A while still wet. Then proceed to paint your darkest sections of hair with mixture C. Don't paint this as a solid mass but keep some of the previously painted colors. “Drop in” other transparent colors, such as Cobalt Blue and small amounts of Winsor Green while still wet, letting them run together. Let the paint do whatever it likes. You will find you have some unique and intriguing results. Let this fully dry before continuing. Paint over all of the hair with clear water to remove any harsh lines which may have developed, being careful not to “lift” much of the paint. Let dry.
Now the hair should have three basic values; highlights, mid-tones, and darks. You should also have many color variations. Begin drawing strands and clusters of hair with pencil over the paint. Keep it interesting by overlapping and weaving in and out, here and there. Don't make one side a mirror image of the other; variation is key. It is fun for the viewer to fiind small bits of purple, green, and red in the hair, even though it “reads” as brown.
Once you are pleased with your arrangement, begin painting details. Use your brown mixtures as well as the colors listed above, individually. When defining the highlighted hair, use very light colors (i.e., Aureolin, Rose Madder Genuine, and mixtures of the two.) Keep these colors warm and light to preserve the sheen of the hair. Paint the strands of hair in some places, while suggesting it in others. Include some lost edges. Blend and swirl. Don't be predictable. Your watercolor hair will be bright and exciting!