Again (as we said before on Dec. 30, ’11) propriety would expect the more distinguished item to be listed last. According to the Sfas Emes, gold is mentioned before silver to imply that the legs were golden since (according to the Maharal in Ohr Chadash) gold is stronger than silver1, and would thus provide stronger support for such a heavy piece of furniture.
1 This is a matter of gemological debate according to class participant RhS. One way gold is stronger than silver is in its symbolic nature. According to Rav Hirsch in his essay, “Jewish Symbolism” (pg. 171), gold is always strong in TaNaCH, whereas silver is sometimes described as “worthless” or “drossy.”