Unless someone does recognise it specifically - RAL/BS number or manufacturer car model and year colours. Then I suggest taiking your pic. to a good paint supplier to see if they know or can show you a range of swatches that might get to it or at least near it. Also keep an eye out for modern cars that might have something very similar if not the same and take note.
Meanwhile - hope someone does let you know - from experience I know it is difficult to identify exactly what you want when you see it. My last resto had to resort to the the Swatch method from a pic seen on the net - bit of a gamble but thankfully paid off in my case.
Good luck!