Not a precedent.
The company I work for has had a certain shade of red and a certain shade of blue trademarked for our industry since the 1970s.
Companies outside our industry can use them, but in our niche industry they are ours.
The Red Sox have had the shade of green painted on their famous left field Green Monster wall trademarked for decades on everything. Tshirts, plush toys, hats, you name it.