Or
Or is the heraldic tincture for gold. Artists paint it either with metallic gold or with a plain yellow, and both count as Or. It is one of the two metals in heraldry, along with Argent, and its name is simply the French word for gold.
Because Or is a metal, the rule of tincture sets it on a colour. The arms of England put three gold lions on red. France Modern, used by French kings from about 1376, is Azure, three fleurs-de-lis Or. In black and white engravings, Or shows up as a field of small dots.
In the coat of arms maker, choose Or by name from the color picker. The starting design already shows a gold lion on a blue field, and Or reads just as well on Gules or Sable. Try to avoid gold on white, since two metals side by side are hard to tell apart from a distance. The Argent entry explains the other metal.