Mud, insects and rainwater have reportedly contributed to the warm-up pool’s bizarre colour.
A lack of basic maintenance has led to other venues falling into disrepair, including the Maracana, Rio’s Olympic stadium.
The arena is without power as city officials argue over who is responsible for paying its electricity bill.
Limited security has also led to theft at some venues, while ceilings are falling in at others, according to Brazil’s O Globo.
The quality of the water in Rio’s diving pool was also an issue during last summer’s spectacle.
It turned a murky green and had to be drained after swimmers complained it was stinging their eyes and making them feel sick.
Brazil spent billions on hosting the Olympics and Paralympics amid criticism that it could not afford the expense – especially just two years after football’s World Cup.
Rio is not the first city to let its Olympic venues deteriorate and lie unused.
Many of the stadiums used in the Athens and Bejing games have also been pictured abandoned and overgrown.