SL Tricks
From Grigbertz
Silhouette Ball
Make two balls, A and B. Both are hollow, and B fits just inside A's cavity.
Give A a transparent outer texture. Give A a colored inner texture. This will be the backdrop for the silhouette.
Give B a colored outer texture. This will be the silhouette itself. Give B a transparent inner texture.
The trick: give both the colored textures listed above a transparency of 1-2%.