As reported by National Geographic, these names river in Colombia acquired due to the fact that her water as if painted in five different colors. So, have yourself a bluish color of the water of the river, green and yellow shades gives the bottom, in some places covered with green algae.
And the red color is given to the river because of her growing algae (Macarenia clavigera). However, especially bright, he is only from September to November. The rest of the time the color of the algae is not as bright, and the river is in appearance not different from other Colombian rivers.