Get click the above "GET APPLET FILE" button (at the end of the first message)!
Here is another simulation I have created many years ago (not with EJS).
It shows a series of radioactive nuclei decay: different color represent different nucleus.
The radioactive nuclei will decay into daughter product, and the daughter nucleus will decay another nucleus.
The original nuclei are color code in [b]BLACK[/b].
It will decay into [color=red]RED[/color] -> [color=green]GREEN[/color] -> [color=yellow]YELLOW[/color] -> [color=blue]BLUE[/color] (and become stable nuclei).
You can change decay time (unit: second) for each stage (from black -> red -> green -> yellow -> blue),
click [b]start[/b] and watch how the number of different nuclei changed with time -- colored traces.