Genmon does support pango markup according to the README line 78 http://git.xfce.org/panel-plugins/xfce4-genmon-plugin/tree/README "The text between the <txt> and </txt> tag can use pango markup for style and color." This has been working until the 3.4.0-1 release. It also looks like the tool and click tags are not getting parsed correctly. Thanks Nathan