The metals are "or" and "argent", representing gold and silver, respectively, although in practice they are usually depicted as yellow and white. Five colours are universally recognized: "gules", or red; "sable", or black; "azure", or blue; "vert", or green; and "purpure", or purple; and most heraldic authorities also admit two additional colours, known as "sanguine" or "murrey", a dark red or mulberry colour between gules and purpure, and "tenné", an orange or dark yellow to brown colour. These last two are quite rare, and are often referred to as "stains", from the belief that they were used to represent some dishonourable act, although in fact there is no evidence that this use existed outside the imagination of the more fanciful heraldic writers. Perhaps owing to the realization that there is really no such thing as a "stain" in genuine heraldry, as well as the desire to create new and unique designs, the use of these colours for general purposes has become accepted in the twentieth and twenty-first centuries. Occasionally one meets with other colours, particularly in continental heraldry, although they are not generally regarded among the standard heraldic colours. Among these are "cendrée", or ash-colour; "brunâtre", or brown; "bleu-céleste" or "bleu de ciel", sky blue; "amaranth" or "columbine", a bright violet-red or pink colour; and "carnation", commonly used to represent flesh in French heraldry. A more recent addition is the use of "copper" as a metal in one or two Canadian coats of arms.