The kind of clear/color paint job you are talking about is done but not common in OE applications. It is an old school trick commonly used with lacquer paint but works very well with modern single stage urethane.
It is a multi step job with a couple of color coats then a coat of 50/50 another of 75 clear 25 color and a coat or two of clear.
This makes it a thick paint job but it will really pop and has the durability of a base clear job. It is also common to do a 50/50 for door jambs, inner fenders, under trunk/hood and firewalls.
Enamels and lacquer are the most common single stage, the lacquer will be thinner and flatter and easier to burn through than base clear but the enamel is usually thicker and has more orange peel.
If you thin enamel down so thin to reduce orange peel it probably has the same thickness as base/clear as it will require more coats. Flattening enamel is where the term color sanding comes from, an extra coat or two was applied for this reason on the better paint jobs of the day.
