What is the difference between a blue or black stamp from U.S. Citizenship and Immigration Services (USCIS)?
As of July 1, 2014, U. S. Citizenship and Immigration Services (USCIS) began using a new secure blue ink for many of its secure stamps. The older secure red ink will be retired and no longer used by USCIS on the effective date.
USCIS stamps with secure blue ink:
Department of Homeland Security (DHS) Parole Stamp
Temporary I-551 Alien Documentary Identification and Telecommunication (ADIT) Stamp
Refugee Stamp (Section 207)
Asylum Stamp (Section 208)
Initial / Replacement I-94 Stamp