A tartan garment, when sold, is often called something like "Ancient
Red Robertson" which looks different from a "modern"
one of the same name. However, the pattern remains the same it
is just the shade of thread used that belong to a different scheme,
There are no explicit standards for colour use and the colours
are chosen by experience by weavers or by thread suppliers, but
the usual types of shading are:-
These have nothing to do with a tartan being old, but is an attempt to
approximate the vegetable
dyes that were originally used to make tartan cloth.
These relate to the bright shades that were first popular when
synthetic aniline dyes were introduced. In those days, only the
rich could afford some strong colours and so there was great enthusiasm
to be able to do likewise.
These go further than ancient colours by attempting the effect
produced by vegetable dyes after they had naturally faded.
These are another, duller form of ancient colours but not always
resembling reproduction colours.