Part of the limits offered by manufacturers is resale value. The boring colours will sell easier than the ostentatious ones. Some are offering different colour schemes by adding colour variants for wing mirrors/roof/stripes.
As for Morgans, well the styling is the major visual and colours are less critical. (Discuss.......).
Howard....it is about time you bought a Morgan. Get it wrapped to whatever colour you want. A 2 tone would add scope.