AP Photo/Morry Gash
 
The pools at the diving venue are green. The seats at the track stadium are blue.
 
Blue, as in, empty. 
 
Runners and throwers played to a 60,000-seat stadium that wasn't half full on the opening day of track at the Olympics on Friday. 
 
AP Photo/Matt Dunham
 
The fans missed some good stuff. 
 
In the morning session, running in front of a quarter-filled stadium, Ethiopian Almaz Ayana broke the world record at 10,000 meters by more than 14 seconds. 
 
In the evening, where the crowd was a bit bigger, American Michelle Carter pulled an upset, knocking off two-time defending champion Valerie Adams of New Zealand to give the U.S. its first medal _ a gold one, at that _ since 1960 in women's shot put. 
 
"I understand shot put isn't the marquee event of athletics,'' said track fan Dave Friedman, who traveled with his wife from North Carolina. "But it's the first night _ and it's Friday.''
 
AP Photo/Morry Gash
 
The fans who were there created a strange atmosphere _ for the sprinters, at least. 
 
American English Gardner said she heard whistling and screaming the entire time she was in the `set' position. Normally, it's dead quiet once the runners take their marks.
 
"Here, they kind of treat it like a soccer game,'' Gardner said. "It was kind of hard to hone in on the gun.''
 
Though IAAF president Sebastian Coe predicted it would be a challenge filling all the seats, there's still hope. 
 
Usain Bolt runs his first-round heat in the 100 meters Saturday, then should be going for his third straight Olympic title Sunday.
 
He'd love people to be there:
 
"It's the first night with rounds,'' American 1,500-meter runner Jenny Simpson said. "My semifinal will be the night of the men's 100. I definitely anticipate that will be different.''