Hi Jason,
the cumulus are form the sky starter pack, the cirrus are yet unreleased, but will be at some point.
As for the overall render, you can see that the biggest part of the scene by far is the sky. That allowed me to up contrast to 0.8, and reduce gamma to 1.8 or so. You have to be careful with exposure, to not white out all the clouds.
In the end, in post, I reduced the saturation a bit and shifted the hue slightly to a lighter blue. And that is essentially it.
Cheers,
Frank
