We're getting close to 2.2 stable! SkIndigo 2.2.9 contains a lot of important bug fixes and adds support for the new Absorption Layer Transmittance parameter (A.K.A. Surface Color). This feature can be used for accurate simulation of things like true stained glass windows, projector film, and skin blemishes. It is used in 'Specular' or 'Glossy Transparent' material types.
Get SkIndigo 2.2.9