The folks who run things at Niagara Falls are in the spirit. The falls has been turned green for St. Patrick's Day weekend. You're probably thinking "How do they do that?" About 5 gazillion gallons of water go over the falls every day. They can't possibly dye it. The Niagara Falls Illumination Board shines colored lights on the falls. LED light shine from three locations in Niagara Falls, Ontario. The falls are illuminated with  multi colored light shows to commemorate numerous occasions throughout the year. The Falls will be lit in blue & yellow March 21st, for Downs Syndrome Day.

[Better Homes and Gardens]