Sorry for the delay in answering here is the information about my configuration 14:22:56: Geany INFO : Geany 1.32, fr_FR.UTF-8 14:22:56: Geany INFO : GTK 3.22.30, GLib 2.56.3 14:22:56: Geany INFO : System data dir: /usr/share/geany Thanks for the info. I followed the instructions : copy the CSS fie into ~.config.geany . But it does not seem to be loaded. Any modification to do in preferences? Another problem is that it does not seem possible to change the display of the current tab.