A purple and pink fire hydrant graces the corner of an intersection in a small Central New York city. The different colors of hydrants have a meaning, but this one is very different.

Credit: Oswego Volunteer Fire Department

At the intersection of County Route 7 and County Route 20, there's an unusual fire hydrant, painted purple and pink. Behind it stands a sign that explains its appearance. The hydrant serves as a memorial to Theresa Moshier, who was 43 when she was killed by her husband in an incident of domestic violence, seven years ago. The hydrant was dedicated by the Oswego Volunteer Fire Department, where Theresa served as a volunteer.

While this Oswego fire hydrant is special, the color of a hydrant and sometimes its caps indicate the gallons per minute (GPM) flow of the hydrants.

According to Business Insider,
Red: 500 GPM or less, for a 2-story house that's 50 ft by 50 ft and 20 ft tall.
Orange: 500-1,000 GPM, for a 4-story house that's 50 ft by 50 ft and 40 ft tall.
Green: 1000-1500 GPM, for a 4-story house that's 61 by 61 and 40 ft tall.
Blue: 1500 GPM or more, for a 4-story house that's 70 by 70 feet and 40 ft tall.

Some colors don't always refer to GPM. Yellow indicates that the water comes from a public supply system. Violet means the water comes from a lake or pond. While most areas follow this color scheme, some choose to make up their own system.