Quote Originally Posted by Scottish Chi
How important is the tartan pattern and colors so as not to look foolish since official tartans were not established until relatively recently? Are there any guidlines for choosing a tartan pattern?

Cheers! Bill
Muted "earth-toned" tartans work nicely. Documentation of the period said that the Highlanders liked colors that worked as camoflage.

In James Aikman’s 1827 translation of George Buchanan’s 1581 History of Scotland: “They delight in variegated garments, especially stripes, and their favourite colours are purple and blue. Their ancestors wore plaids of many colours, and numbers still retain this custom but the majority now in their dress prefer a dark brown, imitating nearly the leaves of the heather, that when lying upon the heath in the day, they may not be discovered by the appearance of their clothes; in these wrapped rather than covered, they brave the severest storms in the open air, and sometimes lay themselves down to sleep even in the midst of snow.”