It's all about the perception. If some people think that the dress is gold and white, it's probably because of the dress being near the window where it's a bright blue sky and sunny weather, while on the other hand these who see the dress black and blue they think it in that way that the dress is in a different setting, preferably with yellow lights.
But the main question is, why is everyone obsessed with this dress? It won't solve the world hunger, for example.
I mean, it can be black and blue or gold and white. End of the story.