The most predominant color in "Sir Gawain and the Green Knight" is naturally green; everything from the Green Knight's tackle to his armor is green. Another recurring color in Sir Gawain and the Green Knight is the color gold. Gawain's knightly armor has gold accents: the knee caps have knots of gold, the spurs are gold, the "least loop or latchet gleamed with gold" on his horse's harness, the saddle has gold fringe, the bridle has golden buttons.
Another color that is mentioned is Gawain's red shield, which is described as being "bright red, with the pentangle painted thereon in gleaming gold."
The color gold is symbolic for Gawain's virtue, "for pure was he as gold, void of all villainy." Of all Arthur's knights, Gawain is the most pure-hearted and trustworthy for such an important task. He proves his honor and worthiness of wearing gold on his task when he repeatedly avoids the advances of Lady Bertilak.