The brain doesn’t just read raw brightness; it interprets that brightness in relation to what it thinks is going on in the scene.

So when someone sees the dress as white and gold, they’re usually assuming the scene is lit by cool, natural light — like sunlight or shade. That makes the brain treat the lighter areas as a white-ish or light blue material under shadow. The darker areas (what you see as black) become gold or brown, because the brain thinks it’s seeing lighter fabric catching less light.

You, on the other hand, are likely interpreting the lighting as warm and direct — maybe indoor, overexposed lighting. So your brain treats the pale pixels not as light-colored fabric, but as light reflecting off a darker blue surface. The same with the black: it’s being “lightened” by the glare which changes the pixel representation to gold, but you interpret it as black under strong light, not gold.