In 2012-2014 I recorded the color of the sky as seen by various webcams around the world, every few minutes.
Click on any lightwave to see the original webcam view (update 2020: most of the websites have now gone offline).
Akureyri is fairly far up north, so we can see a rather pronounced curvature here, indicating short days in winter and long days in summer. The most striking feature of this particular image though is how often the weather is grey in Akureyri — barely ever a blue sky.
The slightly darker patches such as the one that covers all of December, are caused by the camera's white balance shifting automatically when the ground was covered in snow (I think).
Even further north than Akureyri, Alta sees a midnight sun in summer: from May to July the wave is fully lit
Grass in the summer, snow in the winter.
Not a very good webcam in terms of colour quality, but I include it nonetheless because it's where I live. It tends to show she sky as white even when it's rather blue, though.
Nice colours here.
In this one you can see the moon as milky streaks crossing the night sky diagonally.
Amazing image quality on this one, I find.
My personal favourite. The image quality is amazing, the colours are beautiful, and you can see the moon passing through once a month. And you can also see that the weather in Santiago is ridiculously good in the summer, and quite grey in the winter.
Similar projects elsewhere on the Web: