Reply by CplSteel

Some stares require blue on documents filed with the courts. That way you can tell the original from the black and white copies. I have no idea why color copiers have not screwed this up

Doctors like blue because when they check a box on those forms it visiually pops. But I have seen some use black.

Maybe some of each and see what sells better?
I mention it because nice pens like that are probably being bought by people who use pens for a living.