If you've sampled Rainwashed and you feel the connection to the other elements you have planned, then I think you're good to go. Well on your way to creating an overall, pulled-together look.

On *paper* it reads as if it's all adding up to a cohesive look.

Very pretty comforter.
I am also trying to find a nice spa blue like color for our bedroom and finalled decided on Quietude, the next color down from Rainwashed as the depth of it seems to look good with both bluish or greenish bedding. The Rainwashed read blue most of the time in my lighting.
Funny too how I started out with Palladium but found it a bit much.
Good luck with your project and isn't it nice to be able to get moral support when on the fence. I really depend on the expertise of these kind folks here when starting any project.

I've read the good things about Quietude and Rainwashed on the Decorating Forum. When I went out to choose colors last week (2 days to choose for the entire house!), neither color worked because of a strong bias to green. So. I chose Raindrop for an accent in a room painted Rhinestone. Raindrop is almost a marina blue with a hit of gray and Rhinestone is a light silver gray with a hint of blue. Lovely!