The Olympic women's synchronized 10m diving final is currently on, but no one is really watching the divers - they're all wondering why the pool is so green.
Just 24 hours earlier, British divers Tom Daley and Daniel Goodfellow secured a bronze in the men's final in a clear blue pool.
But Tonia Couch and Lois Toulson found the same pool to have been an unappealing emerald colour.
Seriously - look how blue the pool was Monday for the men's final.
And compare that to Tuesday...
Even Tom got in on the act.
What would happen to you if you dived into the green pool? Nobody knew.
The BBC commentators were so confused by the pool's colour that they asked an official what was going on, but they said they didn't know.
It did add a certain something to events.
There are rumours of an official statement being made, so hopefully the mystery will be solved soon...