Ubuntu MATE 20.10 groovy
This "Pluma" code editor comes with Ubuntu mate
(screenshot from https://mate-desktop.org/)
In pluma > preferences > fonts & colors > Color scheme it states:
You can add a new color scheme by clicking on Add..., and selecting a color scheme file
You can remove the selected color scheme by clicking on Remove
Where are these files placed? and are they CSS files? I would like to create some additional themes for everyone to use.
Let's start from the existing ones. For example Oblivion color scheme:
$ dpkg -S oblivion libgtksourceview-3.0-common: /usr/share/gtksourceview-3.0/styles/oblivion.xml
The line above says that this file came from libgtksourceview-3.0-common package.
It is XML file. Its syntax is covered by Style Scheme Definition Reference.
To start hacking one can create local version of Oblivion theme by copying it to the corresponding folder and renaming it to Oblivion-mod:
mkdir -p ~/.local/share/gtksourceview-3.0/styles
cp /usr/share/gtksourceview-3.0/styles/oblivion.xml ~/.local/share/gtksourceview-3.0/styles/oblivion-mod.xml
sed -i "s/oblivion/oblivion-mod/g" ~/.local/share/gtksourceview-3.0/styles/oblivion-mod.xml
sed -i "s/Oblivion/Oblivion-mod/g" ~/.local/share/gtksourceview-3.0/styles/oblivion-mod.xml
sed -i "s/Dark color/Modified dark color/" ~/.local/share/gtksourceview-3.0/styles/oblivion-mod.xml
and then apply this theme and continously edit the file.
Also note that there are some style collections on the net: