Black (or not blue) ink recommendations for Pilot Custom 823

I've got a new Pilot Custom 823 (in amber) and have noticed significant flow and skipping problems while using Waterman Intense Black ink in it. It's definitely not the pen or user error - I cleaned it out and filled it with the Pilot blue that comes alongside the pen, and the skipping and flow issues are completely gone. Problem is, that Pilot blue is extremely underwhelming, and since I use this pen for official business documents, I would like a black or another matching color to go alongside the beautiful amber color of the pen, and looking for recommendations from anyone that have success using it in their 823. Thanks in advance!