My 56 beetle was sprayed with the color you are looking for a couple of years ago. I am pretty sure I have the codes you want.
When I was picking a color, I found some great pictures of Polar Silber on some old 356's, that's what sold me. I get complimented on the color all the time. It is a hard color to capture with a camera/ on the internet. In one light it looks silver, another blue.
There are 2 variations in the Porsche line of colors. Polar Silver, and Polar Silber. The paint guy I spoke to when getting some touch up paint brought in both variations for me. Polar Silver ... which is VERY silver, and Polar Silber which is the blue version.
If you want to see it in person, let me know and we can hook up.
Cheers,
Joel