The new planet, located in the constellation Chanterelle, had a blue color. The first assumption was that it is water, but as it turned out later - it can not exist there even in gaseous form.
HD189733b is very close to its star, the surface temperature on this planet is over the 1 thousand degrees Celsius. The blue color is silicon, which exists at this temperature in the form of molten glass. The whole planet is covered with streams of hot glass. Plus, periodically there are whirlwinds and storms. The wind speed exceeds 7,000 km / h - it is extremely difficult to imagine such a thing in combination with molten glass.