FAT documentation: Blu or black ink?

Dear all,
is it mandatory to use a blue ink pen in GMP validation documentation (eg. FAT protocols)?
I understood that this requirements was newly repealed.
As well, I know that some company policy provide for a black ink.

Thanks in advance for your help!

Not sure if this helps, but the best that I can come up with, is that very old copy machines were unable to copy the blue inks. This resulted in businesses adopting black ink. Mostly, I think it’s tradition… Comes down to company policy and peoples general inability to change. Some places require signatures in ink other than black, so as to distinguish between the actual signed page and a copy.

The use of blue ink is being adopted recently as the regulatory agencies are having difficulty in differentiating between the Original and the photocopies of raw data sheets.

There are few auditors around the globe who has objection for signing the Document with a Black ink pen.
They say " Write all reports with Black Ink pen and Sign with Blue Ink". Their explanation or reason is that when you sign with Blue Ink pen --they will know thats its original document but not a photocopy or a cut paste sort of thing.
The debate continues. I personally think here the colour doesnot matter much in compliance audits.Its how we present data and how effective the documentation is and how we have compiled all data.