Overlap Colors to Create a Blended Look. I like to lightly color the dominate color first and leave a bit of paper exposed for the wax of the second color to cling to. In the liver I colored (below), I started by coloring a layer of red, then I colored some brown on top. Then I colored more red over the top. I find this kind of layering to be really fun!
There's also a kind of colored pencils that's called water_coloured pencils. The way of application is just the same as colored pencils. However, with this media you can achieve a watercolor effect by dipping a brush in water and brushing along the colored areas with it. It's actually a fun media to try especially if you want to use a watercolor but find the mixing with water hard. It's easy to use as well.