Light, King Tut and Gouache

I've mentioned before on this blog that I am in the middle of illustrating a book called Tomb Robbers. Here are a couple of color studies from the book. As always, the quality of light is one of my main concerns. The top image is interesting to paint because of the 2 very different light sources: the very warm lamplight that illuminates the father and mother and the cool moonlight coming in through the door and rim lighting the boy.

 I'm using gouache (opaque watercolor) which I have a love/hate relationship with. I mostly love it but I hate the way it dries at a different value than when it's wet. Makes matching colors/values a little challengeing at times.