Hey Bob
My understanding was that or and argent were metals, not colours. Along with the furs: ermine etc (I can't remember the others - vair?), they form the three pinciple categories of colour/texture on a shield.
Technically, according to tradition, one may not 'charge' (place on top of) a metal with another metal, or a fur with another fur. These rules were, however, often disregarded in the 19th century when everybody and his brother wanted a coat of arms.
These days, I believe, the Royal College of Heraldry (or whatever it's called) is a bit more circumspect about the sorts of arms it recognises or issues.
Speaking of 'proper', in heraldry, it refers to anything shown 'realistically' - including animals. So a heraldic lion (in positions from couchant to rampant!) is quite different from a lion 'proper'. And so on...
cheer
the sunshine warrior
