Colour ideas

I am looking more into what colours I can use and why.

The basic colours I could and am looking at are orange, blue, and (not so important) green

Here is the line-work I will be reusing

 This is the base colours with the line-work

I changed the green to more of a Teal. I also added basic shading

I will now add more colours on top of these base colour, e.g. Yellow sun. Blue shadows from sky.