Teachers, Parents, Students and All Others

This site is here to explore and present optical illusions. If you have any suggestions to improve this site or a particular illusion you would like researched and presented here, please contact me.

If you have self-created illusions that you or your class brought to life, contact me and I will let them live here for all to enjoy.

If you are 13 years old or younger and wish to have your work displayed here please talk with your parents and have them send it to me with their permission.


Watercolor Optical Illusion

This is an example of the watercolor effect. This effect was first demonstrated by Baingio Pinna in 1987.

Simply put The watercolor effect is perceived when a dark (e.g., purple) contour is flanked by a lighter chromatic contour (e.g., orange). Under these conditions, the lighter color will assimilate over the entire enclosed area.

What does that mean? Take a look at the below image. You see 9 distinct squares. The center of each square looks white but the outer area of each square has taken on a watercolor shade, pink, green, yellow, blue etc...

watercolor optical illusion
Tic-Tac-Toe Board
(c)Walt Anthony
Created from samples
provided by Akiyoshi Kitaoka

The truth is that aside from the squiggly lines the only color here is white. The outer ring and the inner square are pure white.

Prove It: You can prove this by using the eye dropper tool in either of the following free graphics programs Paint.Net or Gimp or you can use the eye dropper tool in the free Colorzilla extension for Firefox browser. When you use these tools you will find that RGB value of everywhere on this image that is not a squiggly line is R:255 G:255 B:255 or #FFFFFF.

Print out this image and slide it into a plastic document protector. Now use an earasable marker and you have a reusable optical illusion Tic-Tac-Toe board.


Tannis said...

Hi, I'm in the seventh grade and I'm doing a project on making a magazine (not a real one) and I came here looking for something to use as a short article... :)

Anonymous said...

Sorry... I can't help. But try typing 'current' events into google... that couuld helpif you have not already tried that..

Anonymous said...

~nice website~

Anonymous said...

Saaaah Cool ~_~_~_~_~_~_~_~_~_ :PP

csquadqb17 said...

wow thats coolios! ohno now giant chickens are attacking gtg!

mikky_mouse88 said...

I cant see this optical illusion. Well I dont understand it either, it is to confusing!

Anonymous said...

All work as described except for the top left one. That has colour in the middle.

Anonymous said...


Walt said...

I saved the image and looked inside the top left box and it is the same as all of the other centers ffffff or white.

Anonymous said...

i just did not ge that one it was just confusing

Anonymous said...

Hi, my friend and I were looking for some optical illusions and I found this site. The Tic-Tac-Toe illusion is not real at all.Yet, I do not understand it at all.I you could please explain it to me.Thank you and have a great day!...:)But the other illusions by Herman are great!

courtneymouse said...

this illusion (watercolor optical...) is amazing mostly due to it's color shades. If you don't look hard enough, all colors surrounding the lines are the same. It took a while for me to see it.

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