Although the Earth’s been decidedly blue for 600 million years, rising populations of phytoplankton caused by rising temperatures are once again causing the world’s oceans to turn green.

Some cyanobacteria have pigments that specialise in harvesting green light to power photosynthesis, which may be because they ...

Paris green was another popular choice. These arsenic compound dyes were replacements ... and chalk was meant to help create the in vogue pale face favored by high society. It was also used ...