Very cool. We are launching a sensor that mounts on the inside of your window and measure the sky color for a small cone of the sky and transmits this to our skylight and window fixtures inside (see innerscene.com) so they can replicate exactly the same thing indoors. You could potentially use a computer monitor to do this, but it generally doesn't provide great light due to using RGBs instead of wide-spectrum sources.

One issue with the current code is it doesn’t model clouds, haze, or smoke so the rendered sky can differ from what you see outside (numerous HN comments notice this). You can partially correct for this by using semi-realtime satellite imaging but hard to get super accurate which is what pushed us to develop our own sensor. There are various CCT sensors on the market already but they only measure directional+diffuse+reflected light which is typically ~7500k but the sky color goes up to 40,000k.

Here is a plot showing the color of the sky as it changes during the day from real sensor readings. Each one is 30s apart, so it change change quickly. https://www.innerscene.com/built_pages/cs_specsheet/cct/cct_...

A bit more info as well: https://www.innerscene.com/SpecHelp/CircadianSky/cct/cct.htm...