The 1-D binary Cellular Automata was run using Rule 110 (using the Wolfram naming scheme), and the particle identification was made by arbitrarily assigning colors to different (2d spacetime) patterns. Both the rule type and pattern visualization are explained and user-editable in the tutorial/simulation I wrote for DSWeb here: http://tutorials.siam.org/dsweb/catutorial/ (Just click "Launch the interactive Tutorial via Java Web Start") For example, here is the same screenshot in the context of the simulation application: http://tutorials.siam.org/dsweb/catutorial/screenshots/slides/particles.html