Is this splotchy purple pattern on short ribs ok? We’re making some short ribs, and noticed this weird pattern on the bone side of some of the ribs. What is this, and is it safe to eat?

As a side note, there is some silver skin on the other side of some of these ribs, but this pattern is distinct.
Its ink from a USDA meat inspection mark. The ink is non-toxic so it's safe to eat, just ugly.