My billbergias will also have blue when the flowers have 'dropped' fully...some blue, some green. I got a bunch many years ago, not even knowing what they were or that they flowered...there was a place here called the 'Bird Farm' and they were selling out. They grew billbergias for the birds...the birds would shred the leaves for their nest making. I was amazed when they flowered...couldn't resist them, whatever they were, at $.75 a gallon....lol.
My husband is from Iowa and we did spend a couple of different winters there and I loved the snow, but I think I've decided that I'm too old now for snow...