From what I can find in various publications the RPM range fits roughly with the Merlin, the red segment up to 3000rpm is probably the FULL power range that was only allowed for a very short time, ie start of take off roll until 100ft was achieved then reduced to 2600/2850rpm for the
en-route climb with a further reduction to 2000 to 2400rpm for the cruise.
Many different settings were tried and tested in an attempt to get best range, speed and reduced strain on the engines, especially on heavily loaded bombers, like Whitley, Wellington, Halifax and Lancaster.
Mosquito’s seem to use 3000rpm as the max with 2650 for climb/high speed, and 2300 for long range.

Richard