There are a number of things in the motor that are green including seals.
Considering the issue in your thread here
http://forums.pelicanparts.com/boxster-cayman-forum/814941-code-p1341-came-up.html you may want to consider checking the Vario Cam adjuster solenoid. It can have green seals and if they fail could lead to a CEL.
Your timing chain tensioners can also have green seals.
