The blue background will work (I don't know if it's the photo or just my munted eyes but it looks more purple to me).
You can colour the background and add more to the one you were working on if you like, but if you feel that it's done, it looks done enough to be done :) I like pencil and paintbrush marks, maybe go full watercolour or airbrush or digital if you want it super smooth? XD You can mix it up with and without pencil marks anyway to give that little bit of texture to some of the things.
Both of the colourings look beautiful. When you're done with the river one finish the bunch of flowers one, it's too nice to quit on :) (unless you're not feeling it anymore)
It does look purplely doesn't it? The colour is called Lagoon, I picked it cos of the name lol
I dont think its done. It doesn't feel done but after all the hours I put into it, I'm scared I'll stuff it. Might study pics of the ones other people did some more just to see how they did it.
Thanks hun xx
As for the flower one see how we go, I never really thought of finishing it since I stuffed it early on and it became my test page :D