Even BBC got on the motherfucking dress XD
Spoiler alert, the real dress IS blue and black, cobalt blue to be precise. I see 'white and gold' (well, blue and gold like Master, but gotta pick a side I guess) because my brain interprets the pale blue and brown of the actual photo as being the result of shade. Someone who sees blue and black is interpreting those colours as the result of flash/light. Note how the black and white patterned cloth in the background is a similar shade of brown to the lace, yet because it is folded in such a way that it's obvious which parts of it are in shadow or under light, even whitegolders can interpret it as black easily!
Or at least, that's how I understand the dissonance to have arisen...