Currently, an external lexer needs to supply an .xml file with the language's token and their relevant styles.

e.g.

While this works, the problem, or rather inconvinience is, that if the user selects a different theme, he has to change all the coloring.

For the already integrated languages this is not the case. There are multiple styles for multiple themes under ..\AppData\Roaming\Notepad++\themes

There for every theme, all the supported languages are defined, so each language has it's own settings for any given theme.

Please enable this functionality for external lexers as well.