this is not correct. i have seen a demo where a girl was wearing blue clothes and the system still works.
I think the blue used is not in the video color cube (probably closer to UV than blue) so there is almost no chance that somebody wears this color.

Giroud: it is true that the color is different (with this system you
can basically use any color you want again by changing the colors
of the leds). Mike is correct in saying that the system works in the
same fashion. I've seen the leds in both blue and green for
example.

The difference is the fabric and how the thing is illuminated.
Another difference is price.

It's a lot cheaper to just get a black cloth or some other highly
saturated color. Light it and key that out. It might have some
more trial and error, but it is far cheaper then buying the other
set. Ofcourse which one you can/want to get depends on your
time and money availability.

you are right, the price for this stuff is just unbelievable.
around 800$ just for the LED ring.
you can probably build one just for 50$, but the main problem stays the fabric that has even more unbelievable price.
(several thousand $ for a pretty small one).
Anyway, there is probably some situation where money does not count and this stuff fit the need.
I guess you can probably try to replace it by a silver projection screen for very cheap.
(another project to put with DOF adapter and HD home made)