TIL that a very nice large addressable LED device I'd been given doesn't use NeoPixel order, but APA106 colour order. And also that, despite it being mentioned in MicroPython's Quick Start Guide for the RP2, the APA106 library isn't included in the standard firmware
(easily fixed: copy ports/esp32/modules/apa106.py to the Raspberry Pi Pico's filesystem)

