My thoughts..
I like both bags, Papillon is a great bag however if you get a 26 I think you will kick yourself later for not to get the 30, besides.. the 30 comes with small Papillon, you can use it for evenings or nights out.
I adore the Soufflot
, this this IT bag for me, the leather is strong, roomy, classic, fun and sophisticated, you can dress up or down, wear it over your shoulders or handheld same as Papillon 30, you will not be able to do this with Papillon 26.
I see you are thinking on this two discontinued colors, this is good, because when those bags were made they used thicker leather and hardware is gold.
You can't go wrong with a Soufflot or Papillon 30, but Papillon 26 is way too small, you will end up craving for extra room.