The LED matrix is actually made up of 12 smaller (8x8) boards that are connected together. This requires an interesting (painful) algorithm for getting our color map to display correctly.

As Adam stated in 242560:

Because Jordan soldered the LED matrix without care and respect for the
rest of us, a significant amount of mapping has to be done from the
temperature array to the LED layout.

Adam made a decent attempt, but didn't quite get it right. It also took him a fair amount of convincing that his algorithm was junk, but a few tests and a final working solution put us all back on track.