The "pets" I've seen on the islands have always been some shade of green/yellow. The dwarfs are grey(gray?)

This particular specimen must have been close to shedding. Snakes are often referred to as being "in blue" prior to shedding. Especially noticable are their eyes due to the old skin which is about to be replaced.

Boa constrictors are primarily grey, brown and tan. Any green/yellow snakes are a different species.