The green is the fluro dye every car air con mech uses.
Tape up the offending fitting and hose really, really well tonight.
The bloody PAG oil used by the Japanese compressor manufacturers is highly hygroscopic, it's pretty much toast in well under fifteen minutes exposure to the atmosphere.
When I use POE oil I purge the can with dry nitrogen immediately and PAG is worse.
[edit] Because of the water solubility you might only need water for cleanup. I've never really played with PAG's.

