I want to change the color of the title bar - eviltoast

I think this would do it

https://github.com/the-allanc/minty-color-titles

It says to put it into the .config/gtk-3.0 folder

But I can’t find a .config folder. I found an /etc/gtk-3.0 folder.

Would that directory work?

Is there a better way to change the title bar color?