Thanks, I ran out of ideas for the foreground so I'll give leaves/petals a go. The blue is just sky behind the tree, maybe that isn't very clear?
Aye, the lack of feathering around the edges of what I'm assuming are clouds makes it look more like blue foliage.
I actually reccomend making it that though, the tilt of the tree gives it a really nice sense of vertigo.
I was planning on putting an example picture of the concept, but unfortunately despite spending about 45 minutes looking for it I could not find it. Ergo, I've shoddily recreated it in MS paint:

It was a panel from the webcomic homestuck, if anyone can tell what the panel I mean is. What's important to note is how they curved the radio tower (that thing on the left) to curve over the character looking up at it to give it a kind of sense of vertigo to it. It's a really solid stylistic flourish and one that can really help drive home a sense of scale.