On the snowy scene, your blue is really saturated, and using such a saturated colour for outlines doesn't really work - it makes the outline compete for your attention.
I tried a quick palette edit, which also has some hue-shift and makes all the outlines non-black (black outlines are very harsh, especially against such bright colours)

I'd suggest trying some hue shifting on the swampy location too - currently there's an awful lot of that same green hue!