It is easy to mix beautiful flesh tones with watercolor paint. The luminosity and transparency of the paint add to the depth and beauty of a portrait.
In the Maimeri Blu brand of watercolor paint I love to mix Primary Red Magenta with Permanent Yellow Lemon, both are transparent colors. These two colors are very bright on their own, mix a small amount together on your palette and add a lot of water and you will create a lovely pale flesh tone. Add a little more yellow for a more peachy undertone. Add a little more of the red for a rosy undertone. If you are going for more of a tanned skin tone try a well watered down Burnt Sienna. For darker skin tones you can use Burnt Sienna mixed with Sepia. Mix this well on your palette because they are granulating colors. If you want a deeper dark skin tone add a touch more Sepia to the Burnt Sienna, it creates a beautiful color.
Rosey & peachy pale flesh tone - front & center swatch - Primary Red Magenta + Permanent Yellow Lemon.
Tanned or olive skin tone - top right swatch - Burnt Sienna.
Dark skin tones - top center swatch - Burnt Sienna & Sepia.
Deeper dark skin tone - top left swatch - Burnt Sienna & Sepia.
Mix the colors well on your palette. Vary the amounts of each color to change the under tones. Blues and purples make great shadow colors on all skin tones. The shadows can be applied under or over dried skin tones. If you don't have the exact colors I have, test the colors in your palette. Mix a cool red with a cool yellow, mix a warm red with a warm yellow for the pale flesh tones. Then remember to add lots of water. I bet you have great flesh tones hiding in your palette.