System identification of custom fields when creating a report

I would like to see a system delineation between custom fields and system fields. Often, people have created fields very similarly named or with exactly the same name. It would be great to have a way to do this other than our workaround which is adding a little '`' to each custom field. One option might be to have a light grey 'C:' for custom in front of the fields on a report. This would not show up in the report, but would be a visual indicator for the report writer.