Metals in Heraldry

As I understand it, white and yellow were usually used to represent the metals "argent" (silver) and "or" (gold) respectively, in graphic terms, when depicting a coat of arms. When arms were painted on an object, such as a shield, were metals actually painted in silver and gold? Or were they used interchangeably with white and yellow?

As a concrete example, I've got the arms of a German knight (from the Manessa Codex) which use yellow. When I paint this on the shield, should I use yellow or gold, or would either be possible?

Eric

[ September 30, 2003, 15:34: Message edited by: Ares ]

No, yellow and white were used on the shield and the cloth to represent the gold and silver.