I finally decided to put the vegetation inside the level.
It is slimy, foggy and dark but visible at the same time - just as I hoped it would look like. I want people to think 'Damn, this looks mysterious and tempting but there's no way I'm going in between those woods'. Did I get there? Not yet. Although originally I wanted a dark sky and an environment illuminated just by the moon, I like it better during daylight. There is this contrast between deep ambient occlusion and mid-grey sky. I know I can't go too dark though - the player has to see clearly what's around him.
I applied those variations to my screenshots and painted over them slightly.
There is my red hooded protagonist with an oil lantern. There's a broken wooden carriage floating in the lake. Why is a carriage in the lake?
I recently watched this short animated movie and I adored the use of colours and the contrast between light and dark. This is exactly what I want to achieve.
I love how blues and greens clash with oranges and yellows.