Oh, it's that dress that my folks have bugged me about a few weeks back. Remember that very well, since everyone raved about it so much. I'll share my thoughts from then:
My first answer was that it was Blue and Brown. This was before I was told of the actual colour choices. Blue and Brown. After I was told to pick Blue/Black or White/Gold, I went with Blue/Black.
This is simply because I thought the black was recieving reflected sunlight to look brown - from my own experience I can attest that my very very black hair looks chestnut brown in direct sunlight. Couple that with the quality of the photo, led me to believe that in fact, I was looking at a Blue and Black dress. The Blue also looked like it had a slightly warm tinge to it.
Now here's the thing, if I were to assume that there was a secondary, bluer, dimmer, light-source (lamp? TV? Computer?) and that the sunlight did not go as far as I had initially assumed - I would instead say that light has caused the White/Gold
dress online to take a bluish hue, leaving the gold looking darker and duller too - because of reduced yellow/orange/whatever wavelengths being emitted by the light source, the gold absorbs the majority of the light and reflects less back to our eyes. At least, I think that's how it works.
There's no reason from the picture alone to assume there wouldn't be such a light source...
Essentially, the Blue/Black choice I made was simply because the black>>brown situation via sunlight was more familiar to me than the White>>Blue. Most of the lights in my house are yellowish. My experiences just happened to have leaned that way. Could have easily leaned the other way had my experiences with light have been different. Perhaps if I was in a mostly white/bluish light household instead, I would more readily believe my second reasoning. Could this be the reason both combinations are being touted as viable? (Before the actual colours were revealed, anyway). Perhaps, perhaps not.
I definitely disagree that it has anything to do with colour-blindness, something my relatives have surmised. It might, but I sincerely doubt that is the sole reason.
Part of me wonders why I am taking this seriously. I guess I felt it was just something a bit more interesting than saying how ridiculous this whole thing is.
EDIT: Just skimmed this thread, and that xkcd comic literally shows what I meant in a simple picture. I should've read the whole thread before posting. Sorry for repeating what has already been said, everyone!