@RL_Dane Oh you tried already that :)
in your editor check :
:echo $VIMRUNTIME
That will show your directory where there is a colors dir with all the colorscheme.
There you can edit the one you're using or copy it in your ~/.config/nvim/colors/mycolorscheme.nvim
And, then use that one of course with :
:colorscheme mycolorscheme