What tartan is this please?

[figheadair]

I am once again gob-smacked. I am constantly amazed by the width and breadth of the knowledge of our members. In particular,
the arcane, esoteric, and hard-to-ferret-out info revealed by our favorite tartan expert. As a pretty fair lighting tech, I've worked
with color all my life, but at 71 I am just now encountering darn blue. I'll admit I surmised the possibility, and occasionally the need
for such a color, and am elated to find I was right all along.

You will of course have recognised the typo (now corrected), the result of typing too early in the morning without the benefit of a caffine injection.