Question

when are the clouds violet?
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Answer 1

Answer:

We can see purple and violet colours mostly in sunset, especially when there are less clouds. It is best to see them in twilight, the last part of day light when there is light but sun has almost set. Clear skies, cloudless and least polluted are best to see violet skies especially in the lower most part of west skies.

Answer 2

Answer:

That would be the colour of clouds in the summer evening.