On the right side of my bookshelf, around where I keep a lot of my camera stuff, I have a section of books on Buddhism and related topics.

That photo is quite yellow. The shelf is lit by halogen lights and Christmas tree bulbs. It looks normal enough in person (well, a bit dark) because my mind adjusts to the colour. But the camera takes it and then we see the picture in a different context and we see the colour imbalance. So I reset the balance on the camera using a blank white sheet of paper – actually the back of an airline boarding pass that I have sitting around.

It’s not that that is perfectly neutral white balance. It’s just that it more closely matches our default bias. There is no such thing as unbiased, perfectly balanced colour, any more than there is such a thing as accent-free…