Fog and water clouds appear light pink in the HRV Fog RGB images.
The images left and below show water clouds, fogs in HRV Fog RGB images. This RGB type due to its high resolution is very useful to detect valley fogs.
The image below shows a situation when fog and/or low clouds formed over snow covered surface. The fog and stratus clouds are easy to discriminate from the snow covered surface due to the good colour contrast between the cyan and the light pink colours.
Explanation of the colour of fog and water clouds (see also the recipe on the left side):
The reflectivity values of water clouds are around medium strong both in NIR1.6 and HRV channels. However, after the linear stretching the signal becomes higher in the red then in the other two colour beams. As a consequence water clouds appear pinkish in the HRV Fog RGB images.