Thanks Pete but I can't claim credit for the idea... It was real!!!.
We had a bit of a thunder storm and when it stopped raining I looked out of the bedroom window and saw the rainbow lined up with the chimney, so I grabbed a shot before it disappeared.
Find this quite intriguing, I thinks it's the narrative that make me want to keep looking at it. I didn't think that much of it at first but it keeps growing on me and I really like it now.