Thanks, I've added a yellow to the palette and changed the text the way you suggested, and it is way better now.
A good advice on the mountains too, changed to the (unfortunately saturated) dark blue and it worked nicely.
I'm not so sure about the contrast on the trees though, I don't want to draw attention to there. Besides that, everything looks a bit more saturated and contrasty on my test mobile device - it might be that my display is not really well calibrated.