old: orange means "it is too hot"
new: orange means "we need more heat"

This matches my new intuition (based on looking at the display rather than thinking about code) and secret agrees.

We needed a simple PWM controller at Camp and this board was available...

We need one more level of indirection.

The record number of Modbus is not enough to address 2 MB of flash
memory so we add an additional offset.