The word green comes from the Middle English and Old English word grene, which, like the German word grün, has the same root as the words grass and grow. It is from a Common Germanic *gronja-, which is also reflected in … See more

In optics, the perception of green is evoked by light having a spectrum dominated by energy with a wavelength of roughly 495–570 nm. The sensitivity of the dark-adapted human eye is greatest at about 507 nm, a … See more

Neolithic cave paintings do not have traces of green pigments, but neolithic peoples in northern Europe did make a green dye for clothing, made from the leaves of the birch tree. It was of very poor quality, more brown tha… See more

Green can communicate safety to proceed, as in traffic lights. Green and red were standardized as the colors of international railroad signals in the 19th century. The first traffic light, using green and red gas lamps, was erecte… See more

• The flag of Italy (1797) was modeled after the French tricolor. It was originally the flag of the Cisalpine Republic, whose capital was Milan; red and white were the colors of Milan, and green was the color of the military unif… See more