I recently added coolant to my E70. That was about 3 weeks ago. I park my car inside the garage. This week, on two separate occasions, I noticed a small amount of bluish green liquid underneath my car. I called the shop and told them I suspect it is coolant. They said bmw coolant is usually a blue color. If it is a neon bluish green color, it is freon. The shop must be mistaken because isn’t freon a gas not a liquid?

What would cause it to leak on only a few occasions? It is not everyday that I see the fluid. Thoughts?