The earth is made up of lots of different colors. Dirt and soil are consistently various shades of browns, grays, and blacks. Condensed water vapor in the air (clouds) are brilliant whites. They can turn dark gray for storms. Forested areas will be dominated by various shades of greens. That's because the plants are loaded with chlorophyll containing chloroplasts. Green chlorophyll is the most common type in the plant kingdom. I always like to ask my students what color water is. They always scream out blue at first, which is wrong. Water is clear. But oceans and sky appear blue because of absorption and scattering of blue light. Earth is a lot of different colors. But if I had to pick just one, I'm going with blue. One of my favorite pictures is of planet earth, and it is called "The Blue Marble." So I guess I'm not the only person who would pick blue.