Beautiful image! Thanks for posting.
Not sure about clouds, the blurry parts look more like sand partially covering dark areas. There are mighty sand storms and moving dunes there.
The dark areas are more interesting. What are they? Ice? Last time I checked, ice is white. Pools of liquid water? Not likely with the very low
atmospheric pressure. Maybe micro-organisms or vegetation with dark heat-absorbing color?
NASA used to explain dark stains as dark dry dust:
Dark Streaks Over-riding Inactive Dunes
The alternate explanation is water, with or without life:
Water Flows or Just Dry Dust??
Mars Water, Odd Surface Features Tied to Life
That would be an excellent place for a lander to take samples from.