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.
Like I replied to another comment, how can you explain that the surrounding environment is yellow then? Based on this diagram, white+gold could only work if the rest of the image was lit with blue light... which it clearly is not.
The dress appears to be in the shadow to me (light source between dress and background, with the dress shielding the light source from view in the picture), so it wouldn't be affected by the yellow light.