Is the image at the top of this post in colour? Or black and white?
That's the question that digital media artist Øyvind Kolås is asking you with his new series of visual experiments. He calls this technique 'colour assimilation grid illusion'. (To 'assimilate' is to take, or absorb, something fully, especially to make sense of those things.) Which sounds very complicated.
But what it actually is? Well, it's something quite simple.
Just a pinch of colour
Kolås starts with pictures that are black and white. Then over top of them are laid simple, single colour grids.
Or straight lines.
The end result is an incredible illusion. Your brain essentially fills in the missing colours that it would anticipate, or expect, to be there in a full colour image. True, once you stare at the image for a while, what is actually there can become apparent. (Have another look if you're still not quite seeing it...)
But we're amazed about how as we scroll between the images, the colour assimilation grid illusion begins to work its magic again.
And even better, it doesn't just work on static images. Here, Kolås has applied the technique to an animated clip. Watch it for yourself and assimilate the magic!