The colour scheme of Sora’s heart station as a child in BBS, and in DDD when Riku’s there, is strikingly similar to the colour scheme of Riku’s half of the combined keyblade, mostly blues and purples.

This implies that their respective halves represent the heart of the other, not their own.
When we finally see a dive into Riku’s heart, his heart station will be the same colours as Sora’s half. Golds and greens.

When Dearly Beloved plays during the Symphony of Sorcery, it was intentionally chosen, since a unique version of the song was composed for the scene. Because of this and because they have never talked about the thing, I believe the combined keyblade’s name is Dearly Beloved.
The windows
are becoming stained
with a nostalgic colour ~¤~





