No Prefix Different color water bottles?

My friends have been playing minez for a while but took a long break and just came back. When we came back they threw me a waterbottle and it was the color of a health potion, is this just a plugin bug or what?

This was a water bottle that used to spawn in the spawn kit for a while. It's pink. The item was just a bug I think but it's no different than a normal water bottle.

i've had this happen to me once or twice, and have known others this has happened to, too awhile back but hasn't happened since. I figured it was just a bug as well.