You are correct, and Wolfe also gave orders for his light infantry to brown the barrels of the muskets, although the lights remained in red except for the 80th regiment. The Germans in the AWI are documented at one point to have been told to remove the gold and silver lace and braid from their uniforms.
The problems that I have encountered are when folks find one historic source, and assume it universally used throughout North America. This seems to be a natural mind-set for the 20th and 21st century mind. Folks want simple, and in some cases "one word" answers of "yes" or "no".
Case in point, about 15 years ago many folks at historic sites would tell you that the color yellow was not often seen in Colonial clothing, except in evening gowns, as it wasn't very colorfast, and faded very quickly in sunlight. I wondered then, why did the flags used in Maryland, use so much yellow if it faded in the sun? I found that information came from a Smithsonian report on the natural dyes of New England, that was done about the time of the Bicentenial, so it was then already 20 years out of date. Well New England isn't Maryland, and when we used goldenrod, a natural dye available in Maryland, but not mentioned in the Smithsonian report..., we found yellow to be quite bright, and very colorfast.
So, in answering many questions, you find conflicting information, and often need to be specific to be accurate in a reply (in my experience). Some riflemen used brown in wartime, or other "sad" colors. Other rifle companies, though, wore white, sometimes with red cuffs and collars. One rifle regiment wore purple, with red cuffs and collars. So with this question, as with many, the beginning question is very broad, and you have lots of variations.
Talk about firearms, dyeing, or clothing, you get huge regional differences. Talk about currency, and you've got several hours of studying to understand just the coinage that they used. (I was very surprised the day I discovered that "pieces of eight" were actually bits of cut up coins) There's an article in the current Muzzleloader magazine on the different "hands" that people used when writing (never knew that), and in it is mentioned the different types or levels of literacy as well (I thought it was you could read or you couldn't). Talk about medicine, and you find there are barbers, surgeon's mates, surgeons, and physicians, plus apothecaries. It's not one-upmanship, it's merely an attempt to prevent the continuation of inaccuracy, and it's natural offspring, myth.
After all, how many folks that visit historic sites think we beat the British because we were smart and hid behind walls while the Brits were stupid, wore red, and stood in lines in open fields?
LD