I have not posted a no sky sky for a while so here is one.
We have had some bright weather over the last few days - and when the sky is clear and the Sun is low in the sky we get natural rainbows indoors. I think we get so many bands of colour because of the number of small panes of glass in the window.
I have to say I do rather like refraction - oh the wonders of basic science.
You can find more skies at Sky Watch Friday.