Mono code is a color scheme designed to be neutral. It's dark gray and white but it's tasteful :P
Most color schemes have a base color like blue or purple and overtime they get boring and they don't fit if you have other apps that don't have the color scheme so the intent of this scheme is to look good everywhere even if you have other color schemes being used.
If you would like to help creating ports open an issue on the ports repository. In the future there will be guidelines for terminals and code editors.