I didn't watch the video in details, you're on spectrum mode 10, so act+aux is doing kyber dial. This is a temporary color tuning, it's not affecting the color profile (and thus not saving any modification to colors.txt)
it was chosen to work this way otherwise, it's very hard (visually) for the user to revert to the color (profile) he had set if mis configuration happens, especially when you have memorize the color (profiles) order in your saber
from aux+act => kyber, I engaged profile selection submenu, selected another blade profiles, power off, blade profile got saved for the font, so it's all working as expected