Green, not gold, was the color of the day at the Olympic diving venue.

Sure, China won its third consecutive gold medal on Tuesday, but the buzz was about the color of the water in the diving pool - a murky green.

That was in stark contrast to the pool's light blue color the previous day and also that of the clear water in the second pool used for the water polo competition at Maria Lenk Aquatic Center.

British diver Tom Daley, who earned bronze in the men's synchronized 10-meter event on Monday, tweeted a photo of the two pools next to each other and captioned it: "Ermmm ... what happened?!"

Water quality has been a major issue surrounding these Olympics, but in the ocean and lagoons, not the pools.

A statement from Olympic organizers said water tests were conducted and there was no risk to athletes. They couldn't explain the color change, but said it was being investigated.

Rio spokesman Mario Andrada said the green was caused "by a proliferation of algae."

"This was because of heat and a lack of wind," he said. "We did all the chemical tests. The pool will be blue tomorrow (Wednesday).

"If it were green and yellow, we would know it was a patriotic thing," Andrada joked, referring to Brazil's national colors.

Canada team leader Mitch Geller suspected the cause was algae that multiplied quickly in the day's warm and sunny conditions.

"Everybody was scratching their heads ... I think that the filter is busted, but I'm not sure. It's not really dangerous. It's not like it's toxic or dirty or any of that. It seemed to get worse over the course of the competition," said Geller.

The water wasn't just a cosmetic nuisance - it was so dark that divers couldn't see the bottom of the pool.

"They're used to seeing the water," Geller said. "Visuals are really important in diving."

China's Chen Ruolin, who teamed to win gold with Liu Huixia, said the water color made no difference.

Paola Espinosa of Mexico, competing in her fourth Olympics, noticed the pool getting increasingly darker throughout the six-round competition. But she said the water didn't smell or affect her skin.

(China Daily 08/11/2016 page5)