The rust red for which Heriz rugs are best known, usually set with dark navy and cream in the field and border. The red itself is traditionally obtained from madder root. Local lore adds that the weavers keep the dyed wool for a while in a river of the Heriz area that carries copper minerals, that the copper shifts the dye to this rustic tone, and that this is why the color is tied so closely to Heriz; studies of carpet dyes do not document this copper effect.