Determine an original color

[Rdwsp]

Going to look at a 1970 Dodge Challenger. The people that I'm buying the car from lost a fender tag. How can I figure out what the original color of the car was

 

[DetMatt1]

In the trunk on the bottom side of the package tray there's usually a fair amount of overspray. If the car has been restored it's possible that the entire body was stripped and all the original paint was removed in which case you may never know.

 

[Avalanche]

Without the fender tag, the only way is from the build sheet.
If the plastic back of the front seats were never removed you may have a chance of finding it.
If this car is mostly original the build sheet will add value.