I don't think this explains it fully. This shows how the perceived color has a dependence on the background, but not how it has a dependence on the observer as

I don't think this explains it fully. This shows how the perceived color has a dependence on the background, but not how it has a dependence on the observer as well. In fact, for me, I saw it as white and gold at first. Now, several hours later, it's black and blue and I can't see the gold at all. The background of the image didn't change.