This expansion of the wonderful blue cyan salt ponds at Dead Sea is actually shown in a series of aerial pictures from NASA. The evaporation ponds at the south end of the Dead Sea were first photographed by Space Shuttle mission STS28 in August 1989.
In this photo, you clearly see that the southern half is separated from the northern half because of the fall in level of the Dead Sea. Note that the color is homogeneously blue cyan.
This next picture shot in March 2001 by STS102 shows a new northern extension.
Moreover, the larger pond was subdivided into smaller ones. Finally, the color of the lower basins have changed to a royal deep blue. As shown in the last image taken in March 2012, not much as changed within the last decade.
The pond size, and thus salt production, has expanded substantially in response to global demand for salts used in industrial processing. Beginning of the 20th century, chemists discovered that the Dead Sea began was a natural deposit of potash (potassium chloride) and bromine.
What makes this change in color?
Due to variable algal concentrations, vivid colors, from pale green to bright red, are created in the evaporation ponds. The color indicates the salinity of the ponds. Micro-organisms change their hues as the salinity of the pond increases. In low to mid-salinity ponds, green algae are predominant. (WIKIPEDIA)