The Art of Thermophilic Bacteria
The bright colors found in Yellowstone's hydrothermal basins are the result of thermophiles (microorganisms that not only survive but thrive in extremely hot temperatures).
Trillions of individual microorganisms are grouped together and appear as masses of color.
Different types of thermophiles live at different temperatures within a hot spring and cannot tolerate much cooler or warmer conditions. Yellowstone's hot water systems often
show distinct gradations of living, vibrant colors where the temperature limit of one group of
microbes is reached, only to be replaced by a different set of thermophiles.