optical illusion

[El Gordo]

This is quite interesting. Black and white picture looks like it's in colour:

1) Move the mouse off the picture.

2) Stare at the dot for 30 secs

3) move the mouse back onto the pic

http://www.johnsadowski.com/big_spanish_castle.html

[Sweder]

Whoa . . .

[Mid Life Crisis Marathon Man]

Only just caught up with this one...

Whoa seconded!

[Riazor Blue]

I discovered how this works while waiting for a train in Yokohama some years back. Clever how they have worked the colours out though.

[amber88]

Weird...I did it four times in a row...odd how that works

[El Gordo]

I'm presuming it's something to do with complementary colours. Well OK, it's a guess rather than a presumption......