how are old paint colors figured out ?

Thanks for the replies. I have just never seen another Dart in this color, or those that had it were repainted something else.

Looking at this paint chip sheet, it is paint code ss-1, and and other number under the chip is 81403 and it is called ivory. So I was just wondering how they can get the paint right, if the only reference (the chip) could be faded.

Chip sheet is original... PPG paint, "Ditzler Automotive Finishes"

Will check out those sites... thanks.

rb