Drag to pan, scroll to zoom. At step 0, click a cell to add an ant and click again to turn it; once it has faced every way, the next click removes it.
An ant reads the colour under it, turns the way the rule says for that colour, repaints the cell with the next colour and steps forward. Nothing else, and still: chaos, then order.
Drag to pan, scroll to zoom. At step 0, click a cell to add an ant and click again to turn it; once it has faced every way, the next click removes it.