Hey guys, long time lurker, first time poster lol.
Here's what I've found:
Switching ensembles without applying the changes from the saved ensemble resets the colors on NGS accessories, even if you switch to the exact same outfit. However, PSO2 Classic accessories still retain their color selections. This prevents players from using the /myfashion command to change your outfit to what was intended.
I recorded a video of the issue in a couple different scenarios too: https://www.youtube.com/watch?v=oVS6vGqYKn8
On PSO2, I'd use the /myfashion command in shortcuts to quickly switch outfits during a quest, and I really think the shield ties everything together here. I can't put it on this outfit though with that color scheme! lol