How do I avoid the dull-looking shadow when using chromatic shadow?
Kevin Groves, Wales
Shadow are not black. The dullness of the shadow usually comes with that pure black shadow block and very desaturated grey tones in the shadow areas.
Chromatic shadow is a quick way to give the illusion of details in shadow areas. Often a few strokes of saturated colours in the shade can trick your brain into thinking those strokes are a result of bounce light from the sky light.
To portray physically correct bounce skylight in shades is nearly impossible, or at least very labour intensive, but chromatic shadow is an easy way to achieve the impression of a complex lighting situation.
This artistic approach of shadow is especially prominent among famous watercolour artists such as Australian
You can further tweak the chromatic shadow by having some blue tone to mimic the bounce light of the sky.