The illusion that ruined friendships since 11 years ago.
Do you still see the dress as having the same colors as you first see it, or are the colors changing to you? I always see it as black and blue, and no matter what I do, I can't have my eyeballs see it as white and gold.
The right side is white near the top (nearly pure white, likely sunlight overblown by the photo), there is some generally dark clutter with a spot of red, and then a white or pale beige lit with yellow-ish lighting.
The "beam" is either some light wood, or just the shadow on a ledge; it is made brown-ish because of the yellow lighting's illumination but lack of exposure to the exterior backlighting.
The dress on the left is white and black. Made yellow and dark-ish brown-ish by overexposure and strong yellow indoor lighting.
Fundamentally, and the science points to this, you are likely seeing the environmental yellow as actual colors, and not the result of lighting; which I understand on paper... but I cannot see a scenario where blue lighting would produce a bright yellow when overexposed; even if there is yellow in the actual object colors (because blue-ish light would tarnish the warm colors to light grays or possibly light greens I guess)