Hot pink light in sky during "sunset" time during white nights of the summer.

My roommate and I were up talking in the middle of the night, during the white nights, when it was like sunset at the darkest of the night.  She was standing by the window and I was looking at her.  I noticed outside up in the sky completely unobstructed was a hot pink light hovering where nothing was.  It was slightly moving back and forth...only slight, like a "tremor".  I kept staring at it.  She finally asked what I was looking at and I said a hot pink light in the sky.  She looked out and was amazed too.  We both watched it until it left.  I can't remember HOW it left now... if it vanished or just shot off, but it was one of the two.  I brought up at work the next day (as a joke) that I saw a UFO the night before, and the doctors at the table took it very seriously and told me it was a common site over the city there.
Date is approximate.  We have arbitrarily assigned a date.  PD