She climbs through the closet to get to the attic, where her most private memories are stored. In every other room in the house, her outfits are monochromatic - one note, one side, one aspect of who she is - but here in the most private place in the house, she’s allowed to be her true self.
The closet is also where her yellow outfits are stored – where she takes her heart (deep blue) and paints it golden.