"To wear the tartan of a clan one has no association with simply because one finds the colors groovy is, to my mind, rather superficial and silly."

"How the Scots Invented the Modern World" and several other books I've read said that clan chiefs used to pick up new kilts often, regardless of the tartan, when they'd travel. Those books also say that most chiefs seemed to take the philosophy, the louder, the better.

So a groovy color or sett was exactly what the chiefs used to look for.