Blue Rose-ringed Parakeet
Rose-ringed parakeets occur in various color mutations, this being the blue one. Interesting fact: some were held as a pet in Western Europe, escaped, and adjusted to survive in and around European cities. So there is a small chance you'd see one of these in the "wild".
The rose-ringed parakeet, also known as the ring-necked parakeet, is a gregarious tropical Afro-Asian parakeet species that has an extremely large range.