I followed the advice found on this forum and tried cleaning my engine then using powder to try to find the oil leak. So far the only thing I see is some green discoloration of the powder on the shift lever. Is this what I was looking for?

Probably not.  The shifter shaft IIRC just holds the shift lever and the actual shaft going into the engine is connected by a linkage.

Probably not.  The shifter shaft IIRC just holds the shift lever and the actual shaft going into the engine is connected by a linkage.

+1.  That is absolutely, positively NOT your oil leak.