It's all a scam, really:
They either didn't white balance the image properly, or edited the image to make it ambiguous. People just see it one way or another because their eyes are trying to properly "white balance" the image, but don't have a good reference to do so. So I made this image (at the link above) with color references to make it really easy to see what actual colors are in the image itself.
You can also see a lot of examples online where if you look at it on a darker screen, the brown turns more black, and the blue looks darker, whereas on a lighter screen, the brown looks brighter (gold, even), and the blue gets washed out to look almost white.
Don't believe me? Open up a screenshot of the original image and do what I did, try color-picking some colors from it and see what you find - you will probably find what I did, assuming you find the same "original" image that I did.