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.
Sitting for hours can cause poor circulation which is a major cause of the heavy legs syndrome and if there no underlying medical condition and the feeling worsens when walking upstairs, then curiously enough, you might like to look at your diet for clues.
Ad. Another serious cause of swelling in one leg is a blood clot inside the leg. This will sometimes cause a lot of other symptoms, such as pain and a noticeable lack of feeling or blood flow in that leg. In other cases, it may be more subtle and difficult to detect.