[ Thanks to Mike for this link.
]
“An easy way to make ordinary white cloud on blue skies
into dramatic significant parts of your photographs. This is a very
simple trick to do in GIMP and the results are great!“1. Starting
* Open your image up in GIMP – preferably with plenty of
sky!
* Duplicate your Background Layer (set to multiply):
* And go, Colors –> Components –> Channel
Mixer: