It's seems a tropical paradise... but the water is very, very hot! In fact, this is a detail of a thermophilic bacteria colony in Yellowstone N.P.'s hot spring. The incredible colors of the hot springs of Yellowstone are derived from thermophilic bacteria colonies which have found ideal living conditions. Thermophilic bacteria are of different types and color the waters with colors ranging from blue to green, to yellow, to orange, to black, to white, depending on water temperature and its depth