Desert areas appear white and urban areas appear bluish green. Lakes, rivers and oceans appear in various shades of blue, dark blue for deep water and light blue for shallow or turbid water. Image of clouds taken by the STS-63. This is an image of the sunrise from space over the South China Sea. The brightness of the colors in the atmosphere in this photograph is due to the amount of dust in the atmosphere.
More dust is found in near the equator.
There are various sources for such upper level dust. Many dust storms in Africa and ash clouds from major volcanic eruptions are two reasons. This is an image taken of cumulonimbus clouds in the atmosphere. This is a satellite image taken of clouds. This is another satellite image taken of clouds.