A collection of different engines, and many rules per engine are randomly chosen.
The individual engines can be turned on or off, depending on what you want.
Check the various engines in the menu on the left for detailed information about each one.
The colors are initially randomly chosen, but then increment by 1 degree of hue each second, so in 360 seconds the colors will repeat themselves.
Most of the boards are initialized with a random distribution of cells. Cell states are also spread out among the number of states as determined by the rules in use. For the one-dimensional boards, obviously this would be a line of randomly chosen cells. The only exception at the moment is Random Wires, which is a series of lines drawn on the board.
The most common behavior has a number of cell states that are iterated through based on the status of the neighbors, and possibly taking the current cell into account.