Does anybody out there have the paint code for the silver color on a 1966 250 single scrambler?
Yes and No
. Your apparently simple question has a somewhat complicated reply ...
When your bike was made, "paint codes" such as you are familiar with weren't used. Instead, each paint manufacturer named and coded his paints using his own systems.
The original paint supplier to Ducati was a company called Lechler. It's still in business today and, most graciously, they publish a list of the paints, with their names and codes, that were used at the time. In your case, it was a paint that they called "Grigio perla met" (metallic pearl grey) and which they coded as "DUC A10".
However, this name and code will obvioulsy mean nothing to a modern paint supplier!
Paints were not supplied to the paint shop ready mixed. Instead they were supplied as components, with the actual paint being mixed on site as needed. Inevitably, this gave rise to subtle varations in tint, depending on who was doing the mixing - the yellow used on some of the late Desmo singles and the 750 Sports is noteable in this regard.
So what does all this mean?
1. You can't simply go to your local paint supplier quoting the paint code of the time. Neither can you perform a simple conversion of Lechler's code to a PPG or other equivalent.
2. If you're lucky, someone has been down this path before you, and found an equivalent modern paint. This is the case for the later wide-case Scramblers, for example.
3. You could try approaching Lechler and asking them for more info about what went into the paint. I don't know whether this works or not.
4. You can take a sample of the original paint and ask a paint supplier to match it. This is ok if you want the finished job to take into account any discolouration that might have occurred over time.
However, if you want a 'fresh out of the factory' finish, you're likely to be disappointed. Many of the paint finishes achieved by Ducati at the time were WAY better than the 'run-of-the-mill' finishes today, especially when it comes to metallized paints - such as your grey.
5. Another solution: Find a good painter, explain the situation to him, ask him to spray up some sample panels and chose whatever you find the best.