First, we knew astronauts spied the beautiful blue Earth from lunar orbit on Christmas Eve, 1968:
Next we had Voyager II’s view of the sun’s planet number 8:
Astronomers found that when the planet HD189733b passes behind its star, HD189733, as seen from the Hubble Space Telescope, there was a drop in blue light hitting the HST. Conclusion: the planet must be a deep blue color. It also rains molten sand (some media outlets are calling it glass), winds gust to 4,000mph (that’s almost Mach 6), and daytime temperatures hit 2,000 degrees F.
Not a hospitable blue, that.