My 2-cents. It depends on what you mean when you say "not the color we were expecting" As Steve said was there an agreement? Did you tell the builder dark walnut or did you tell him natural cherry? If you told him cherry then stand your ground firm. On the other hand, and though this may not be the case with you, I have seen many cases where a homeowner was just plain dissatified with a color that they requested and tried to hold a builder liable which is unfair.