Knife Painting in Progress

I managed to get into the studio a couple of times in the last few days but, unfortunately, I can't paint for very long at one sitting. My leg starts to cramp up.  I started this with only a palette knife but during the second session I couldn't resist picking up a brush.  I have been watching knife painting demos on youtube but it is a lot harder than it looks!  I found the palette knife much more useful when putting in the details, (like the birch trees and the twigs in the grasses), than when doing the original block in.  This is a very good subject to try all different brush and knife techniques as I am really a novice at landscapes, trees, and meadows.
When I return to the studio I thought I would make the mountain in the back cooler and work on the grass line on the right before adding any more detail to the birch trees on the left and the grasses every where else.  I am waiting till I am satisfied with the snow before putting in all the larger twigs in the foreground.  I keep adding more and more color but for some reason the end result still looks rather monochromatic.  I welcome any and all constructive comments or suggestions.