Say a character ends up being swallowed by a monster, for the sake of an example say the monster is a Kraken.

The rules for being swallowed by a Kraken include this sentence:

While swallowed, the creature is Blinded and Restrained, it has total cover against attacks and other Effects outside the kraken, and it takes 42 (12d6) acid damage at the start of each of the kraken's turns.

So I take that to mean if one swallowed character's allies outside of the Kraken drops a spell on it like Fireball or Prismatic Spray, then they won't be affected.

Does the same apply in reverse? If the swallowed creature casts Cone of Cold while inside of the Kraken, are the creatures outside of the Kraken also able to be hit by the spell or not?