Blue parakeet with yellow head and silver leg band

I lost my blue parakeet yesterday around 3pm near Court Street and Main Street in downtown Binghamton. It's a small budgie, about 6 inches long, with a blue-green body, bright yellow head, and white wings. It wears a silver leg band engraved 'KB-23' on its left leg, which should help identify it. The bird is surprisingly friendly and will respond to a whistle and a gentle clap. It means a lot to me—it's been a companion since my grandmother passed away, and I really need it back.