I don’t usually write about “internet things” like this, but this one basically put me through the stages of grief – I was convinced it was a certain colour, I denied all other possibilities. Then, when I saw it as another colour I became angry with myself for being such a useless biological fool. Then I did the best I could, sneaking looks from the corner of my eye, checking other versions of the image trying to somehow bargain for reason. I then put my computer down, annoyed and depressed that I couldn’t stop the flip-flopping colour change even when I KNEW what was happening! Now, I must accept that – as rare as this is for me – this “crazy viral” natural illusion is actually pretty good.