Were our oceans once green instead of blue?

Pale green instead of blue: Until 2.4 billion years ago, our Earth was probably not a blue planet – it was more like a pale green marble. Because the first oxygen produced by photosynthesis provided suspended particles that colored the seas green, as researchers have determined. This green light era has left traces in the photosynthesis pigments of cyanobacteria to this day. Only when the earth's atmosphere became oxygen-rich did the earthly "li…