Not a problem! It's really overwhelming when you first jump into the code.

Two files to check for this are export_descr_buildings.txt and export_descr_character_traits.txt - do a search for colonia and see if anything comes up. I didn't get any matches in either, so there are no buildings which use the colonia as a requirement and no traits which build off of the colonia for any faction. This means it is completely safe to remove anything from (or add anything to) the faction requirement list.