How do you balance dark and light hues in a painting?

Values in the natural world range from white to black with all the values in between. In our paintings, especially if one is working in a representational manner, attempting to capture light and shadow, one should attempt to replicate this effect. Otherwise, the viewer quickly realizes that something is not right!

Painters of the renaissance, Caravaggio in particular, carried this to the extreme with Chiaroscuro! Light was extremely bright, and shadows were extremely dark. The painting above utilizes some aspects of this quality.

There are particular colors, in watercolor, that are better choices than others to begin with. Paynes Gray is one such dark color. Alizarin Crimson is another. It's better to start with dark colors than to add black. The mixture of Paynes Gray with Alizarin Crimson makes a beautiful, dark Purple.