Hi Lex,
It is better to use named styles rather than setting hard colours, then your filetype will also adapt with loaded colour schemes.
Ok. I found an example of that in filetypes.Python and I copied it.
To get highlighting you need to specify a lexer using the lexer_filetypes setting, see http://www.geany.org/manual/current/index.html#settings-section
Since there isn't a GNUPlot lexer you need to specify something "close enough".
Ok. I tried to do this. I can get several lexers working (Perl, Python, C, Tcl) but the Bash lexer doesn't seem to do anything. No matter, the Perl and Python lexers seem to work fine.
Thanks!
Cheers, Daniel.