Purity Heart

The Purity Heart was an artifact created by the Ancients in Super Paper Mario in order to counteract the Chaos Heart. According to Merlumina, the Purity Heart was divided into the 8 Pure Hearts in order to protect them from evil. Once the four heroes collected all the Pure Hearts, they would combine to make the Purity Heart, thus shattering the Chaos Heart and stopping the Void.

It can be seen at the end of the game twice: first when Tippi takes the revitalised Pure Hearts to Mario during the Dimentio fight and they all converge on her, and also when Tippi and Count Bleack get married to stop the Void, when all the Pure Hearts join together. It is thus revealed to be a golden colour.