These are syntax highlight text color schemes for Gedit (or apps that use GtkSourceView).
Some of these were made for Gedit 2 (GtkSourceView 2) and might need some tweaking for Gedit 3 (GtkSourceView 3), but they still work for the most part. Some might be duplicates, but I saved 'em just in case. Enjoy. The 2.0 files work (for the most part) with 3.0, but I haven't tested the 3.0 files with 2.0.
Place them in /usr/share/gtksourceview-{2,3}.0/styles/, corresponding to the folders in this repo. You can replace /usr/share/ with ~/.local/share/ to install locally instead of systemwide.