Tammy, Christel, Terri. Thanks so much!
Terri, the ref photo definitely had a bright light saturated sky. Starting with that silver grey allows you to go lighter with white when you need that highlight. I either use that or another light grey (leans blue) for sky. Save the white for final highlights and things you want to bring out. Still love my nupastels! They are so easy to quickly sketch, compose and build up the first layer or two. Has definitely saved me a ton of $ and learned new skills by using a hard pastel.