@costales : Pantheon dont have extensions but you can have plugins ( i had Dropbox plugin) but i dont know how it works; I have an idea, i dont know if you are going to like it, you can use org.pantheon.files as a database to save the new folder color for every folder (that have been changed); i dont know if its possible..but still have hope to use your extension on elementary os too
@costales : Pantheon dont have extensions but you can have plugins ( i had Dropbox plugin) but i dont know how it works; I have an idea, i dont know if you are going to like it, you can use org.pantheon.files as a database to save the new folder color for every folder (that have been changed); i dont know if its possible..but still have hope to use your extension on elementary os too