I never knew there was such a thing, obviously, as my editor has pulled me up on this a number of times. The rule is that you don’t put commas between adjectives unless they are of the same class. There are nine (!!) classes of adjectives, and you order them a certain way. I’ve had to study this article to brush up on it: http://theeditorsblog.net/2014/04/08/keeping-adjectives-in-line/
For example, I had written: “Freya sidled up to a gnarly, old apple tree that grew in the front yard.”
It’s been corrected to: “Freya sidled up to a gnarled old apple tree that grew in the front yard.”
No comma, because ‘gnarled’ belongs to the shape category and ‘old’ the age category.
Similarly, “the collar of the pale blue, homespun shirt. ” has been corrected to “the collar of the pale blue homespun shirt.”
I think it’s going to take some practice before it becomes second-nature.
