Dark clouds: Nimbusgreymetallic is a cool grey tone that is reminiscent of the colour of a cloudy sky. ‘Nimbus’ means ‘dark cloud’ in Latin; in meteorology, the nimbostratus cloud is considered a classic bad weather cloud. Nimbusgreymetallic was originally an Audi colour. It has a slight blue or green undertone and appears soft and unobtrusive.