I am not sure that I understand the problem. Are you trying to get people to make changes to the buildings from what was there when the design review was enacted or are you trying to get people to correct violations with changes they made after the design review ordinance?
It is basically impossible with the language of most ordinances to make people change a building's appearance if it was like that when the district's design review started. You can suggest things they might want to do and get the city to back facade renovation grants. Some changes can be conditions of application for other related or nearby work such as fixing a cornice when attaching a sign over it, but mostly it is just hard to legally require a change.
If it is about violations, that is a different matter entirely and where you really need your elected officials and/or judges to understand and support preservation as others have stated.