Referencing the FTIT/Tach "red zone" or the second of those bugs...
In my experience with the F-15C, which is kinda "dated" (old) Those old "steam engine" gauges never had any red, green, yellow markings on them. Its was up to us, the crew chief, to put those zones on them with a paint pen. So, if we had other concerns with getting the jet ready for flight those kind of "window dressing" things fell by the wayside. As a pilot you knew from memory what the good, bad and ugly of those readings were.