Here are the parameters you can pass to the Faces applet, explained in more detail as to their function.
The mode can either be "interactive", which gives you lots of scrollbars, allowing the interactive manipulation of the various settings; or "auto", which does a random generation of settings.
The size of the faces can be controlled by this handy parameter. It should be pretty obvious as to its proper use.
The speed at which each new face is generated. Only valid in "auto" mode. (nota bene: It is currently valid in either mode, but don't expect this behavior to last)
Style can be one of "right" (for "Right Brain") or "left" (for "Left Brain"). Left brain style fills a 8 x 8 grid with identically sized faces. Right brain style fills the entire space up with randomly sized faces.
Color can either be turned on or off. If that's not enough for you, hack the code ;) It has nothing to do with true color.