Phrobis black blade

[Carlo]

I was looking on ebay and this auction got me thinking
http://cgi.ebay.it/Phrobis-M9-Bayone...item56396f6218
A four line blade without the buck markings on the back of the blade.
What is strange?
Well, the black color!
I'm quite sure that some years ago the same seller had a second generation M9 (flat top "M") in black color for sale.
What do you think?
Was the blade originally bright and then later parkerizied?