Nah, it’s actually possible to see each version. There are actually three: white and gold, blue and black, blue and brown. It’s like those “magic eye puzzles”. It just kinda pops into place when it happens. Depending on the lighting in your room and what colors your eyes have recently been looking at, your eyes will see it differently. It has partly to do with how what you “see” is a hodgepodge of signals all being processed into one “image” and the way we process color.
You are correct tho, objectively the image is a specific RGB value and has a defined “color”. That whole divergence between what it is and what it appears to be is the very subject of all those research papers.
I believe one of the ways to easily defeat this trick is to put the dress on a person. The skin tone will act as a known reference point for the rest.
Adding to the requests for a name. I put your post into Gemini and it gave me a few choices, but all clearly wrong, before giving up and saying “it must be some obscure indie title”.
Tried again with the “deeper thinking” version. Reus by chance?