Originally, the TRs left the factory with the standard "Vinylide", unless leather was selected and ordered as an optional extra detail. At that time, only the seat cushions and backs were supplied in leather.
Whe I bought my TR3A brand new in May 1958, it came with red vinyl. But I had no tonneau cover and with the sunshine, it soon went orangy-red. When I did my restoration, the correct red vinyl (original) was no longer available so I ordered the entire interior made in leather. Hides can be dyed any colour you want and that's what I wanted. An interior colour that was like the original and that some parts (like the vinyl) wouldn't fade.
It's still all one colour as it was 21 years ago when I installed it.