Ford could have used something like the ST Line version to appeal to buyers who want more optional color choices or a higher level of equipment. Volkswagen and Mini brands used frequently changing color offerings and trims to broaden their appeal to buyers.
Ford actually went the other way after 2015! They dumped bright reds, blues and yellow. Even silver! The color choices became very narrow, outside of a couple of bright but costly and difficult to repair extra cost shades. Ford went against every rational marketing dictum.
I'm going to be looking for either a pepper red or green ST Line with a manual transaxle in a couple of years. Both of those colors really pop.