Higher than normal ocean temperatures cause coral reefs to bleach, and eventually die. But occasionally during hot spells, corals confounded researchers and turned bright colors of neon. New research published in Current Biology states that coral reefs turning red, blue and neon is a last attempt to protect themselves from eventual bleaching.

According to researchers, coral reefs produced a lot more pigments than usual when exposed to certain wavelengths of light. Plus this neon coral reefs phenomena was observed, in a survey of coral bleaching events around the world, to occur during mild heat stress. Researchers believe the neon colors may act like sunscreen, in order to create an environment that helps bring back the algae responsible for feeding and keeping the reefs colorful.

“We reconstructed the temperature history of known colorful bleaching events around the globe using satellite imagery. These data are in excellent agreement with the conclusions of our controlled laboratory experiments, suggesting that colorful bleaching occurs in association with brief or mild episodes of heat stress,” says Dr. Elena Bollati, co-author of this study and a researcher at the National University Singapore, in a statement.

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“Bleaching is not always a death sentence for corals, the coral animal can still be alive. If the stress event is mild enough, corals can re-establish the symbiosis with their algal partner. Unfortunately, recent episodes of global bleaching caused by unusually warm water have resulted in high coral mortality, leaving the world’s coral reefs struggling for survival,” says Dr. Cecilia D’Angelo, Lecturer of Molecular Coral Biology at Southampton, in a statement.

Recent reports believe that colorful bleaching occurred in some parts of the Great Barrier Reef — the world’s largest coral reef cluster — which gives scientists hope. However, they still assert that while some parts of coral reefs may have higher recovery rates than others, there is no way to stop the reefs from dying — apart from slowing down global warming by controlling greenhouse emissions.