Colorado River

Colorado means "red color". A reference to the red sand that gets
washed into the river when in rains. Further downstream, below
several dams, the water is clear and blue as the lakes formed by the
dams allow the red sand to settle to the bottom
(https://picasaweb.google.com/lh/photo/PmV4EAHGftCKcTZuJR-Pkt2UbL51viCelWWNFj9KrIc?feat=directlink).