Kitaoka's color spirals are a well known color illusion. I have argued elsewhere that they are not really an
illusion, but rather cases in which different colors are instantiated. Such figures put under stress our notions of
To play with such cases I wrote a small piece of code that can generate several cases like them.
You can download the code from here (it works on Microsoft Windows with installed Framework 4.0)
These are a few of the images it may generate.