Skies and pools both darkened Wednesday as the sun-splashed Olympics in Rio de Janeiro gave way to gray clouds and murky green waters.\u00a0The Rio Games were drenched in rain and continued questions about why the diving well and water polo pools look so much like neglected aquariums. The third day of the men's water polo tournament began in green-tinged water, though not nearly as dark as the neighboring diving pool at the aquatics center. It was crystal blue the day before. Water quality has been a major issue surrounding the Rio de Janeiro Olympics, but in the ocean and lagoons, not pools. A decrease in the alkaline level in the diving well Tuesday afternoon led to the green color, organizing committee spokesman Mario Andrada said. He added that the pool for water polo and synchronized swimming is being affected in the same way but ''we expect the color to be back to blue very shortly.'' A U.S. pool expert said that might not be so easy: ''Once you get behind, it gets hard to get back in front of it,'' said Jerry Wallace, chairman of the California Pool & Spa Association, a trade group. Rio organizers insisted the athletes weren't at risk in the green pools. They were on the waters and slippery roadways, though. Strong winds rattled palm trees along the coast and whipped up waves on the scenic lagoon where rowing was postponed for a full day for the second time this week. With winds too blustery, rowers packed up their oars for the day as cyclists hit slick roads on skinny time-trial bikes unsuited to harsh weather conditions. Under dark skies, the cyclists faced lashing rain and wind on the time-trial course along Rio's southern coast. The conditions might have cost Ellen van Dijk of the Netherlands a medal. She slid off the road and got tangled in weeds before finishing fourth. American Kristin Armstrong won the race. Even after a grueling night at the pool, Michael Phelps cruised through the preliminaries of the 200-meter individual medley. With a dazzling 15.8 on the high bar, Kohei Uchimura, the superstar gymnast from Japan, won the men's all-around title on Wednesday night, edging Oleg Verniaiev of Ukraine by less than a tenth of the point to capture his second straight Olympic gold. Defending champion Mexico was eliminated from the men's soccer tournament with a 1-0 loss to South Korea. In boxing, Kansas fighter Nico Hernandez is guaranteed to win at least a bronze and become the first American to medal in the Olympics since 2008. Other highlights from Day 5 at the Rio Games: DEFENDING HIMSELF : In light of American swimmer Lilly King's finger-wagging display toward Yulia Efimova, the Russian who was allowed to compete after a last-minute appeal, the question is how will fans and media react when Justin Gatlin hits the track Saturday for the start of the men's 100 meters. Gatlin, busted twice for doping violations, isn't concerned. ''The system has worked,'' he tells the AP. EBNER ELIMINATED : Nate Ebner, the safety for the New England Patriots who took a break from training camp to fulfill his Olympic dream, sprinted from almost halfway to score a try in the right corner against Fiji to make it 24-19, piling the pressure on Madison Hughes. But the U.S. captain and goal kicker missed the conversion from out wide, leaving the margin at five. Less than that and the Americans would have advanced. ROWING AT RISK : Twenty-two races, including the first two medal races, were postponed in the regatta but international rowing federation director Matt Smith said there's still room on the schedule without having to resort to drastic measures - even if competition is also called off Thursday. LIFE'S A BEACH : The American beach volleyball team of Jake Gibb and Casey Patterson has been eliminated from the Olympics on a tiebreaker. It's the first U.S men's team to fail to advance out of pool play since the 2004 Athens Games.