While bleaching is associated with the stark white skeletal remains of corals after they have lost their live tissue, an opposite effect can also take place when such an event occurs.

It's known as colorful bleaching, where corals seem to amp up their pigments and provide brilliant displays of neon color.

Colorful bleaching has been observed since 2010 in coral reefs around the globe, but the mechanism and reasoning behind it hasn't been understood.

When the corals die, reefs collapse and decline, and so does the ocean biodiversity that depend on them.

Significant bleaching events occurred during record ocean temperatures between 2015 and 2017, causing the most widespread and devastating mass coral bleaching ever recorded, according to the study.

Controlled experiments were carried out at the University of Southampton's Coral Reef Laboratory, exposing common corals to different types of light and conditions.

They discovered that the bright colors actually act as a protective layer similar to sunscreen when their algae are lost — and the colorful process actually acts like a blinking neon sign that encourages the algae to come back.

As the recovering algal population starts taking up the light for their photosynthesis again, the light levels inside the coral will drop and the coral cells will lower the production of the colourful pigments to their normal level."

During the lab experiments, the researchers were able to re-create the ocean temperatures that occurred during colorful bleaching events.

The cause of the colorful bleaching may lie in less extreme ocean-warming events that are brief and mild, the researchers determined based on their experiments.

Or it could be a reaction to changes in nutrients the coral receive from their environment.

This provides some hope that corals and coral reefs can recover, especially given that some recent reports have suggested colorful bleaching in parts of the Great Barrier Reef during a mass bleaching in March and April of this year.