This site will explain the McCullough Effect illusion, and allow you to deliberately induce it in yourself.
Essentially, it causes one to see nonexistent colours in monochrome scenes that contain only stripes. Pic related will seem tinted green and pink if you have induced the effect.
There are plenty of similar illusions; the interesting thing about this one is its longevity. After a few minutes of induction, most people will see the effect for months. For some people, it will never go away entirely.
So... fair warning. Stay away if you do colour-sensitive work.
What the fuck. It's been a couple minutes and it's still there, feels weird.
However I see green in the vertical lines and pink in the horizontal, which is the opposite of what the brainwash shows you.
I heard on a YouTube video that you'll see some fucked up colors for up to a month. Not permanent, but still...
It's not the image in my OP that does it, that's just a test pattern to see whether you've been induced. (When viewed white a bright background as intended, the gaps will seem coloured if you have.)
The inducing images are coloured and need to be looked at in sequence. It's all covered in the link.
If it's any consolation, it only applies to specific patterns/stripes. Unless you're photoshopping zebras behind bars, it's actually quite unlikely to affect your work.
If you stared for that long you're going to be seeing the patterns everywhere for months.
It's been months since I last did it.
I'm not sure, but I do think the upper right and lower left square in your pic still seem somewhat reddish to me. I don't see anything green, though.