Indeed, the cars of the early 70's were painted in an array of rainbow colors from electric blue to sepia brown. Simply that what was available. For some Sepia Brown is viewed as an undesirable color despite its popularity when introduced. It would be crazy if one was to avoid purchasing a longhood strictly on color choice rather then originality. Sepia Brown was Dr. Porsche's preferred color and he had his favorite model. the 928 painted in Sepia. Maybe because it was considered more conservative then the other colors offered. A Porsche salesman who has been selling Porsches for over 30 years remarked to me recently, "the Sepia cars were more favored by the country gentleman" back in those days.
When I bought my 73.5T it was in Sepia. Sure I could have opted to spend 5-7K for a repaint, but I decided to keep it as original as from the factory. If your buying a longhood I recommend you keep it in the original color for its beauty, investment quality and respect for a great car from a bygone era.
My 2-cents
Bob
73.5T in beautiful Sepia of course