The Beech-green Carpet (Colosygia olivata) is a species of moth in the Geometridae family.This species is found in Scotland, north England, and north Wales, inhabiting woodlands and mountains. This species is similar to the Green Carpet, and can range from green to a yellow. There are several crosslines and bars, and a small black dot on the forewing. The outer area has several black dots. The wings have a dotted border. The yellow forms are similar to the Yellow Shell.