I'm experimenting with color variations of the offset square pattern, as seen here.
This one just substitutes dark red for the white squares of the previous version. The four red squares are only held in place by gravity; the 9 black squares are actually fastened in with a stud. -- Edit... you can easily fasten the loose squares to a plate behind the pattern, using a 2x2 brick to fit right in.
I'm looking for a certain look, and I haven't found it yet, but I think I'm getting closer. I'm pretty limited in my color selection, for now, which is why everything is white, black, or dark red. :-)