I had the same experience with the first S. purpurea I ever got which came
from a 5 and 10 in one of those tiny plastic dome containers. I bought it as
a pretty apple red seedling, it grew up indoors into a completely green
juvenile, when it reached maturity I put it outdoors and in no time it was a
completely deep reddish-purple plant. Still have that plant today. It's
amazing what direct sun outdoors will do to the coloring of some plants
(GENERAL WARNING: make sure the species can take direct outdoor sun in your
climate, some can't take it in any climate).
I now grow all my Sarracenia outdoors because of this and two other main
reasons 1. Since the pitchers fill up with insects in no time outside it
saves me from having to feed them, and 2. They got TOO BIG and I ran out
of space.
Plus, there's just something fascinating about watching plants catch
their own wild food without human interference right in front of your
eyes in a matter of seconds. You can't really do the same with VFT's or
sundews, they also catch wild food but the chances of you being there at
the moment it happens are pretty slim, you most likely will come across
prey already stuck to Drosera tentacles or a closed Venus trap. Seeing
a flattened gnat on a Pinguicula leaf isn't exactly something you'd call
exciting, but watching yellow jacket after yellow jacket dive bombing
your Sarracenia in quick succession is a memorable experience! :-)
Regards,
Demetrios