The pink color of pink lakes is primarily caused by microorganisms that thrive in highly salty environments. The main contributors are a type of salt- tolerant algae called Dunaliella salina and certain types of halophilic bacteria or archaea, such as Halobacterium salinarum or Salinibacter ruber. These organisms produce carotenoid pigments (the same type of pigments that give carrots their orange color) which give the water its distinctive pink or reddish hue. The pink coloration depends on a combination of factors including high salinity, warm temperatures, and sunlight, which allow these microorganisms to flourish and produce pigments. Specifically, Dunaliella salina synthesizes beta-carotene, a red pigment, as a protective mechanism against intense light. Halophilic bacteria like Salinibacter ruber produce a pigment called bacterioruberin that also contributes to the color. The pink intensity can vary with conditions such as salinity levels, rainfall, and temperature, making the hue sometimes stronger or weaker. In some lakes, disruption to salinity due to human activity or natural changes has caused the pink color to fade or temporarily disappear. In summary, the pink lakes are pink because of the carotenoid pigments produced by salt-loving microorganisms living in highly saline water environments.