... The Clouds of Jupiter . ... Credit: Voyager Project , JPL , NASA Explanation: What makes the colors in Jupiter's clouds ? With a mean temperature of 120 degrees Kelvin (-153 degrees Celsius) and a composition dominated by hydrogen (about 90%), and helium (about 10%) with a smattering of hydrogen compounds like methane and ammonia, the blue, orange, and brown cloud bands and the salmon colored "red" spot are hard to explain. ... NASA Official: Jay Norris. ... Publications with keywords: Jupiter . ...