Well, You're exploring, learning this one's "best attributes".
The hatching in the upper portion (UP) is most distracting to me--the red-violet more than on the blue areas. Possibly in part because I think it is overhead, a"sky", then I want to see a lighter area closer to the land/horizon. So perhaps a varying of pressure would help (me). And/or perhaps more blending of the lower sky portion. Or, which you probably don't want to do--I wouldn't--(but I do it anyway to get the affect I want)--is to use pan paints to glaze some areas.
The only area of "clouds" that jumps out is the varied angles of the dark blue on the VRight area.
Fluid paints are in MY estimation, generally MUCH friendlier. Unless I'm tearing my hair out at them! (in fact, it's why I don't use either oil pastels or oil bars often, though I have a pretty full set of colors of each...

I also have acrylics, but haven't had them out for a long time, going for the gouache instead.
So for areas you want white, either leave that space uncovered, or use a lot less pressure if you do color it. You would probably have some mixing, so white would be tinted, not white. I wonder if using an acrylic gel medium on that space would work. I've used it with OPs a time or two to my satisfaction.
I've reworked a few pieces for learning purposes.
Best wishes.