compressor oil of greenish colour

What is the effect on a system whereby the compressor oil is of greenish colouru

Hi Noora
Welcome to the forum.
Without knowing what refrigerant and what grade Oil you use?
My initial guess would be "Has someone used a Oil additive /Leak detection Dye in your system?
What is the oil like?
Thick, Thin (Viscosity)? Clear or got bits in it?
How old is the plant? When was the Oil last changed.
Where in the system are you seeing this Green Oil?
More questions than answers I am afraid.
Grizzly