These extraordinary clouds are Nacreous clouds. They are formed in the lower stratosphere over polar regions - so very unusual here, so far south. A bit like Noctiulcent clouds the clouds are illuminated by the sun which is just below the horizon. The colour is formed by the sun hitting the ice particles in the very cold clouds, which can be between 70,000 and 100,000 feet above sea level.
The word Nacre comes from an old English word meaning Mother of Pearl.
What a treat to see this. I stood and watched the colours change before my eyes, until the lower clouds obscured it completely.
