Any question answered...

Ages ago I saw an episode of 'imagine', I think, that featured an artist who would build white rooms with odd-shaped windows looking up at the sky. the light in the room would cycle through colours as the day passed, and the colour of the sky would change too. sometimes contrasting, sometimes complimenting. it was mesmering in timelapse. I think he was building a massive version in a desert out in the states.
What was this guy's name? My google-fu is weak today :(

That's James Turrell. The episode was on the topic of light. Turrell is currently finishing his epic lifetime project 'Roden Crater'. A dormant volcano which he is excavating and re-engineering to play host to a collection of sky spaces, light rooms vaults and chambers. He also has a solo retrospective at Moscow's Garage gallery at the mo, is currently in the Venice biennial and was featured on a thread on this here forum when showing last year at London's Gagosian gallery.