The longest surviving colours will be the drab ones chosen by the most elderly original owners, White Gold, Wedgewood Blue, Snot Supertallic, etc etc etc.
This is generally as they will have lived a cossetted life, low mileage, garaged, etc.
As a point of principle, I would never again buy a car that wasn't a really nice example, in a really nice
colour
These cars look ace in dark colours, which highlight the chrome brightwork beautifully, the same thing cannot be said of the dreary and drab silvers, greys and other light colours.
To this day I rue selling my Mk1 ZT in Anthracite in favour of the drab silver Primer of the MK2 ZT.
How a colour can make a difference to how you feel about a car is amazing, JFM, lovely, CEV, lovely, CDX lovely, HFF delightful, MBB boooring, LEF super drab, HEF yuk, GMN no no no no NO!!
The shortest time I've owned a car ever is four hours.........the car was white gold
Brian