You won't find a specific regulation.
What you will find is that a fair lending exam evaluates your marketing practices. Studies have shown that individuals are more likely to make purchases from businesses that have advertising that includes people who look like them. If all of your advertising contains pictures of a single race, ethnic group, age group, etc. you may find that your volume of applications from minority groups is less than that of your peers which could result in fair lending criticism.
_________________________
Sola Gratia, Sola Fides, Sola Scriptura, Solus Christus, Soli Deo Gloria!
www.tcaregs.com