Kitty must only really have one spencer. This is the only spencer that I have seen her in. If you watched the 2007 version of Persuasion, this spencer may look familiar.
Front View: Really, there are only two fabric colors: a purpleish, greyish color (would it be called a light puce?) and a darker purple. The collar and cuffs done in this dark purple appear to be velvet or velour.
Close-up of Front View: There appear to be two darts on Kitty's spencer.
Partial Side View: Just a side view. You get a closer view of the black buttons.
Back View: To me, it looks like the back is one piece, not the typical Regency back with a couple of pieces.