Clouds are one of those things that I always struggled with painting. Before I learned this method, the clouds I painted were basically white blobs. The key to painting somewhat realistic-looking clouds is to paint them in multiple layers, starting with a darker color first and working your way up to the lightest color (which in this case was white.) I used a few different shades of purple mixed with cool gray for the base of these clouds, but you could use any color you'd like. Check out my YouTube channel (Megan Weller) for a more in-depth explanation!
Products I used:
Arteza Acrylic Paint (set of 60)
Acrylic Paint retarder: https://amzn.to/2EpfPLE
Canvas: Dollar Tree