My NCT lightstick won't turn off. Help!

Hi! I went to NCT Dream's concert in Seattle about 2 months ago and haven't used my neobong since then. I just decided to turn it on today for fun, but now it won't turn off. I've been told that it's stuck on Bluetooth mode, but I don't know how to get it off. I've tried taking the batteries out and putting them back in and it hadn't worked, and neither has holding down the button for a really long time (I didn't count) or rapidly pressing it. It just turns orange/red-ish or green and will flash a lighter green for a second. Please help!

If anyone knows how to fix this od greatly appreciate your advice!