Researching on the internet, scenographic set model boxes. I found some really great ones which could be a good influence. In terms of colour these picture show moods very well.
 Blue and Green.

Examples of white set model boxes, helps me with the initial idea of how small or big things should be in comparison to size/scale.

This model box is much like how mine will be in the sense of being simple. Geometric shapes and muted colours (bland).

These two are good influences for trees. I like how one of them the trees are upside down, gives great mysteriousness and fantasy to it.
The second picture also excites me, its very simple with few trees, (simple being the outlined trees with black a clear cylinder)but very viney. Too viney for my model box.