You could also try to manually control the style for a specific language as well. You would have to catch certain events such as NPPN_BUFFERACTIVATED and NPPN_LANGCHANGED . Any time a certain file was shown, you would manually call Scintilla messages such as SCI_STYLESETFORE etc for all the styles your plugin uses. It is not the “recommended” way but may be what you need. Note that you won’t be able to modify this style through the style configurator.