I am just getting into the War of the Grand Alliance period and just like I found with the ECW, uniform details vary from source to source. For instance, for the Orleans regiment:
Charles Grant, From Pike to Shot - white coat, red cuffs, red waistcoat, white breeches.
Mark Allen, WI article (forget the exact issue) - grey coat, blue cuffs, red waistcoat, red breeches.
They are similar, as I understand many of the "white" coats of the period were actually a grey color (though Grant lists some coast as grey/white and others as white), but the cuffs and breeches are the exact opposite. Many of the unit entries are like that.
Barry points out in one of his QnD guides that the most important part to get right is the coat and cuffs. Other details vary. Uniforms wore out quickly and replacements were made from commonly available cloth like in any other war, so trousers especially could vary.
That doesn't help in the situation above where the cuffs are completely different, but in that instance I get to choose what fits into my plan better. If I already have two units with blue cuffs, I might opt for the red for variety, and point back to my source if pesky questions arrive!
Heck, if some accepts that eighteen models represents a battalion, they should be able to accept the odd unit with colored lace on their hats!