Deep convective clouds with strong updraft – severe convective clouds – often appear light blue in Cloud Phase RGB. The reason is that…

RGB Color Guide
This guide will come in handy for matching colours in RGB images with cloud type or surface feature. It also works the other way round: you can select a meteorological phenomenon and ask for the colour that shows the phenomenon in a given RGB combination.
The collection contains the standard RGBs created from the MSG/SEVIRI imager and also some RGBs from the VIIRS and AVHRR imagers.
To analyse the colours of an RGB image, an interactive tool can be downloaded from the "All Resources" pull-down menu (RGB Colour Tool).
The descriptions of the recipes of used RGBs can be found under the "User Manual" menu (RGB Recipes).
RGB Color Guide
Thick ice clouds covered by large ice crystals appear medium blue in Cloud Phase RGB.
Dust clouds usually appear tan in VIIRS Cloud Phase RGB. Dust clouds are usually semi-transparent. Its actual colour shade depends both…
Open water bodies (outside the sunglint region) usually appears black in VIIRS Cloud Phase RGB. In some special conditions it might…
Sandy desert appears yellow in Cloud Phase RGB. Rocky deserts appear yellow with brownish or reddish shades, or grey.
Vegetated land appears brown in the Cloud Phase RGB. The shade of brown depends on the vegetation type and the green vegetation fraction…
Bare soils and deserts usually appear brown or tan in the VIIRS True Colour RGB images.
Volcanic ash clouds usually appear brownish or tan in the VIIRS True Colour RGB images.
Biomass smoke plumes usually appear bluish grey or grey in the VIIRS True Colour RGB images. The smoke of an oil fire is black.
Water rich in suspended matter or shallow with sediments on its bottom appears greenish or blueish cyan in the VIIRS True Colour RGB…
Deep, clean water bodies - most parts of oceans and seas – usually appear dark blue, almost black in the VIIRS True Colour RGB images,…
Thin clouds appear grey in the VIIRS True Colour RGB images. Very thin ice clouds are not seen.