Change theme colors

Hi!
I am using 1.0.2014 both in Win10 and MAC Mojave

I am aware that you can change how the editor and the render look with CSS, but I was wondering if there is a way to alter theme colors.

I am using Nord, but I would like to desaturate it.
Not going all the way to Dark, more like a set of dark greys like Typora.

Any help pointing me in the right direction would be much appreciated.

Nothing?

Just changing the color of the Sidebar text color would be extremely helpful.
I have a hard time reading that blue-ish tone.

Many thanks Tessus, I found the theme from uxamanda and was able to understand how to do the modifications I needed from there.