So what's up with the water at the synchronized diving pool? 

Here are some before-and-after pictures. In each set, the first picture is from Monday, the second from Tuesday. 

 

China's Lin Yue, bottom, and Chen Aisen compete during the men's synchronized 10-meter platform diving final in the Maria Lenk Aquatic Center at the 2016 Summer Olympics in Rio de Janeiro, Brazil, Monday, Aug. 8, 2016. (AP Photo/Matt Dunham)

Britain's Tonia Couch and Lois Toulson compete during the women's synchronized 10-meter platform diving final in the Maria Lenk Aquatic Center at the 2016 Summer Olympics in Rio de Janeiro, Brazil, Tuesday, Aug. 9, 2016. (AP Photo/Matt Dunham)

 

Britain's Tom Daley, bottom, and Daniel Goodfellow perform a practice dive before the start of the men's synchronized 10-meter platform diving final in the Maria Lenk Aquatic Center at the 2016 Summer Olympics in Rio de Janeiro, Brazil, Monday, Aug. 8, 2016. (AP Photo/Matt Dunham)

United States' Amy Cozad, top, and Jessica Parratto compete during the women's synchronized 10-meter platform diving final in the Maria Lenk Aquatic Center at the 2016 Summer Olympics in Rio de Janeiro, Brazil, Tuesday, Aug. 9, 2016. (AP Photo/Matt Dunham)

 

So ... something apparently changed. British diver Tom Daley, who won the bronze medal in the men's 10-meter synchronized event on Monday, wondered on Twitter. That's the diving pool on the right. 

 

Good question. 

“We don’t know exactly what happened,” organizing committee spokesman Mario Andrada said. “And we don’t know yet why the pool changed colors.

Andrada says the water was tested, as it is every day, and the results "were exactly the same." 

"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 for the kale-colored water was algae that multiplied quickly in the day’s warm and sunny conditions.

Canada's got a guy _ Geller said a Canadian pool expert was coming Wednesday and would offer to help Rio organizers chemically treat the water if there’s a problem with the pool filter.

The Twitterverse had fun with the answers.