The colour used for the mountain in the top picture is too pink so, after completion, I washed out much of the mountain colour and applied one with a stronger ultramarine base. (As in the lower picture, which is an improvement).
I'll be doing this picture again as it was a challenge and worth doing in colours that better complement each other.
The effect of 'low cloud' trapped in the valley is a 'happy accident'. which I am pleased with.