Space Telescope Science
Hubble has identified the true visible-light color of a giant Jupiter-sized planet located 63 light-years away. The planet has a cobalt blue color. It has torrential 4,500-mile-per-hour winds that are so hot they melt silicates into raindrops of molten glass. And that's where the cobalt-blue hue comes from, not oceans. The glass droplets scatter blue light more readily than green or red light.
The planet's color provides unique clues to the atmosphere and weather on a truly alien world that orbits much closer to its star than the innermost planet Mercury is to our Sun.