@pamish 8 March 2021 more from that month

Caño Cristales (English: Crystal Channel) is a Colombian river located in the Serrania de la Macarena province of Meta, and is a tributary of the Guayabero River. The river is commonly called the "River of Five Colors" or the "Liquid Rainbow," and is noted for its striking colors.[1][2] The bed of the river from the end of July through November is variously colored yellow, green, blue, black, and especially red, the last caused by Macarenia clavigera plants (family Podostemaceae) on the riverbed💙💙