Great question Kris!

Water has an intrinsic color, and this color has a unique origin. This intrinsic color is easy to see, as can been seen in the Caribbean Sea and in Colorado mountain lakes. Pure water and ice have a pale blue color, best seen at tropical white-sand beaches and in ice caves in glaciers. Because the absorption, which gives water its color is in the red end of the visible spectrum, one sees blue (the complementary color of orange) when observing light that has passed through several meters of water. This color of water can also be seen in snow and ice as an intense blue color scattered back from deep holes in fresh snow. The river color depends on the source of the river and the collection of water in the water cycle, i.e., precipitation, ground water, surface runoff or glacial silt.

Blue river water. Basically water is a blue colored chemical. Suspended particles reflect blue tinged light back up towards the surface.

Salmon River, Idaho

Turquoise-colored river water traditionally is a result of rock flours and glacial sediment suspended in the water.

Chilko River, British Columbia

Green-colored river water is usually derived from algae.

Navua River Gorge, Fiji

North Fork American River, California

Brown river water means that there are muddy streams running into the river, and there are high turbidity levels with suspended solids.

Colorado River, Grand Canyon