I'm not so sure a court will determine that the town can't enforce its own ordinances or that this particular ordinance in unconstitutional in some way.

Literally hundreds of towns across the country have similar ordinances that dictate house colors in historic districts and even the types of lighting that can be used. I know of towns in MA and CT that only allow black and white for retail signage. I think the towns ordinance will stand along with the towns ability to enforce it.