I had a Green Period at Paint-Your-Own-Pottery night tonight. It really was a lot of fun. Remember that the size of the light source of any picture is revealed in the highlights in the scene. Sometimes the shape is revealed as well. In the green pools of paint you can see several light sources- two fluorescent tube lights and some overhead lamps.
Nikkor 18-105mm f3.5-5.6
105mm - ISO 800