class FamilyMerchant < Merchant COLORS = %w[#e99537 #4da568 #6471eb #db5a54 #df4e92 #c44fe9 #eb5429 #61c9ea #805dee #6ad28a] belongs_to :family before_validation :set_default_color validates :color, presence: true validates :name, uniqueness: { scope: :family } private def set_default_color self.color = COLORS.sample end end