What color is each planet?

What are the true colors of each planet in our Solar system? I've seen the same planet colored differently in different photos.

Here are the true colors of major planets to the best of my knowledge (spacecraft photos appearing in the media often have false coloration):

Mercury: grey; Mercury has practically no atmosphere, so we just see the rocky surface.

Venus: yellowish-white; we can only see the thick layer of colorless and featureless sulfuric acid clouds. You can find more detailed info on Venus here.

Earth: light blue with white clouds; oceans and light scattered by the atmosphere make Earth prevailingly blue. Depending on the area seen in an individual picture, brown, yellow and green continents can be seen or parts of Earth can be covered by white clouds. Earth is by far the most dynamic planet when seen from space.

Mars: red-orange; this color comes from rusty rocks on the surface since the clouds are rare and thin.

Jupiter: has orange and white bands; the white bands are colored by ammonia clouds, while the orange comes from ammonium hydrosulfide clouds. Neither of the four "gas giant" planets (Jupiter, Saturn, Uranus and Neptune) has solid surface so all we see are just clouds in their atmospheres.

Saturn: pale yellow; white ammonia haze covers the whole planet and partially obscures redder clouds below. Currently Saturn's northern hemisphere is blue. Scientists think that because the rings are blocking the Sun in the north (it's winter in the north of Saturn right now), things are colder there and the ammonia clouds are lower down than normal. This gives the rest of the atmosphere more of a chance to scatter light, just like the Earth's atmosphere does.

Uranus: light blue; the color comes from methane clouds. In some photos released after 1986 "Voyager 2" fly-by Uranus looked bright green, but that color was artificial.

Neptune: light blue; like in the case of Uranus the color is due to methane. The surface of Neptune appears darker than that of Uranus due to dimmer illumination (greater distance from the Sun).

Pluto: light brown; Pluto has never been visited by spacecraft, so the light brown color is an expectation based on the presence of dirty methane ice on the surface. See this link for details.

Also, I would like to add that the assignment of colors is somewhat subjective. For example, one person's "blue" might look more like "green" to somebody else. Astronomers rarely care about that, and use precise spectra when they need to obtain information from an object's color.

September 2002, Matija Cuk (more by Matija Cuk), Rebecca Harbison (more by Rebecca Harbison)

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