Geany-filedefs is a project mainly written in ..., it's free.
My Geany colors I work with.
If You have Geany 0.16 or higher, just put the files there: ~/.config/geany/filedefs
If You have Geany 0.15 or lower, just put the files there: ~/.geany/filedefs
And restart Geany. Here you are!
Licensed under MIT (aka X11) license. You can use'em freely! :D