Colour Theory research

As I am one of the people that will be colouring some of the environments and Characters, I have started trying out some different techniques and doing some research.

Experimented with a Split-Complimentary colour harmony. Warm colours coming from the exit, getting colder the deeper the cave gets. 

In this picture I experimented with using cold colours with only a warm colour for the light in the windows. One of our environments will take place in forest a night. 

This is one of the books I have started reading. Specifically for colours at this point.