This is just somewhat conflating a lot of things. There is a dress with some colors, there is a photo of that dress with different colors because of the specifi

This is just somewhat conflating a lot of things. There is a dress with some colors, there is a photo of that dress with different colors because of the specific lighting conditions the photo was taken under and whatever processing the camera performed, and then there are the colors people perceive when looking at the photo, again influenced by all kind of factors. And there is reality to all of them, the actual color of the dress, the pixel values in the photo, and the perceived colors. But whatever color you see looking at the photo does not change the pixel values in the photo, and the pixel values in the photo do not change the spectral properties of the actual dress.