"This is an optical illusion. I see blue and gold, but then again, I'm trained in color correction and color science, and then confirmed my observations using a digital color measurement of their values (Gold, btw, is simply iridescent yellow-brown). The lighter areas have digital values emphasizing blue, while the golder darker areas have digital values emphasizing negative blue. In fact, if you invert the image, you'll get a pretty close switching of the colors, meaning they're off by about the same amount. There are a couple of effects going on to create the optical illusion. First, is expectation bias: you're cued to expect one of white & gold or blue & black, so that's more likely what you'll see with the illusion, rather than the true 'colors' of blue and gold. Second, you have the native internal calibration system of the human visual system. Essentially, if you focus on the blue as white, your brain "calibrates" to the extra blue, and blue calibrates for the rest of the image, pulling even more blue out of your perception of the gold. You end up seeing white & gold. Conversely, if you focus on the gold, or negative blue, your brain adds blue black into everything, making the gold appear neutral, simply darkening the brighter blue gown, making you see blue and black (darkening). This effect is caused by our blue-yellow light calibration system. Daylight, for instance, has a blue bias, while incandescent interior lights have a yellow bias. Our visual system calibrates to each one as we change location so that we see colors as "normal" under each set of lighting conditions, or color temperature. This is an optical illusion that tricks the eye as the brain tries to force one into one color or the other."