Courtesy of BoM

There are ten main cloud types, which are further divided into 27 sub-types according to their height shape, colour and associated weather, Clouds are categorised as low (from the earth's surface to 2.5 km), middle (2.5 to 6 km), or high (above 6 km). They are given Latin names which describe their characteristics, e.g. cirrus (a hair), cumulus (a heap), stratus (a layer) and nimbus (rain-bearing). Clouds generally look white with some clouds appearing to be grey or dark grey according to their depth and shading from higher cloud.