Have you had a look in the boot on the near side just above the lights? There should be a placard with your paint code engraved onto it....if it is the orignal colour. There was also a thread ages ago with some common TVR codes posted.
Be wary, recently fitted the Tuscan s spoiler to mine and they used the correct paint code. It came out a shade off so thy had to redo it using the colour swabs. This is the best way and guarantees the correct colour.