OK, I lied; this one isn't entirely finished. Please excuse the debugging output. The forward/backward buttons below lack arrows, and only the first and last puzzles are actually sensible.
The idea is to correctly colour the board to reveal a picture. Clicking the left mouse button on a square will cycle the colour of that square, the RMB will cycle in the opposite direction.
The numbers in each row/column tell you the lengths of the runs of " filled in" squares in that row/column. The colours of the numbers are irrelevent (they just make the game a little easier on the eyes). It is recommended that one colour be used to mark squares which are "definitely filled in", and the other for squares which are " definitely not filled in".
If you make a mistake, you will not be told (that would make the game too easy anyway). In future, I'm going to try to add some AI to this.
Why is it so big? Have a look at the last puzzle...
Any comments/suggestions? Send them to william@soton.ac.uk