I’m testing out Gnome on another computer, and was surprised by it’s easy customizability, but one thing that seems to be much more difficult than it should by searching it up was… customising the colors? Is there really no easier way than complex commands through the terminal?
The easy way? Install a custom theme. The not so easy way? Edit the CSS the same way themers do.
If you refer to the shell and gdm, see this:
The rest is gtk+ theme 1:1 as already mentioned.