Universe Today
Mercury:
The surface of Mercury is very similar in appearance to our Moon, in that it is grey, pockmarked, and covered in craters that have been caused by impacting space rocks. As a terrestrial planet, Mercury is also composed of mostly iron, nickel and silicate rock, which is differentiated between a metallic core and a rocky mantle and crust.
Venus:
This image of Venus comes to us thanks to the many flyby missions that have taken place over the years. These include NASA's Vega 1 and 2 missions during the 1980s, followed by the Galileo (1990), Magellan (1994), and the NASA/ESA Cassini–Huygens mission in the 1990s. Since that time, the MESSENGER probe flew by Venus in 2006 on its way to Mercury, while the ESA's Venus Express entered orbit around Venus in April of 2006.
Earth:
This leads to our planet having its "Blue Marble" appearance, along white clouds covering much of the skies. The surface features, depending on what one is looking at, can range from green (where sufficient vegetation and forests are to be found), to yellow and brown (in the case of deserts and mountainous regions, to white again (where clouds and large ice formations are concerned).