BTW several years ago I got into a discussion with an American guy who knew a bit about Scottish military uniforms who claimed that Scottish Highland regiments were issued Olive Drab kilts during WWI, due to a shortage of tartan.

(American English "olive drab" is equivalent to British English "khaki". AE "khaki" is BE "light khaki". Makes discussions of uniform colours go round in circles sometimes.)

I told him I wouldn't believe it until I saw some sort of evidence.

Well he pulled out a load of photos of The London Scottish, black & white photos. I tried to explain Hodden Grey to him. I don't think he believed a word of it.