Complete gardening newbie here.

Several months ago I bought a small cactus plant from my local garden
center here in Yorktown, VA. It has 5 cactus. Or at least 4 cactus
and 1 other kind of plant.

On top of a light green stalk was a bright red cactus... and it has
now gone all brown. The stalk doesn't feel alive to the touch, either,
and looks kind of dessicated.

I don't actually remember what the plant thing looked like, just that
it had nice purple leaves, which are now all crumpled and defunct as
well.

My question is have these things actually died? (The other three
cactus in the pot still look nice and green and alive). Or have they
gone dormant.

When I first noticed the red one had lost its color a few weeks ago, I
tried to water it...didn''t help. Prior to that I'd never watered the
pot at all.

Ihttp://www.geocities.com/nocturne_cvs/ExRedCActus.JPG

is a photo of it. The cactus in the middle is the ex-red cactus.

Any help appreciated.