Bled, here means edge to edge, very close?
They had been at a party, the three of them, held at one of the junior editor’s
parents’ apartment in the Dakota, in which art-hung room bled into art-hung room.

Question

Bled, here means edge to edge, very close?
They had been at a party, the three of them, held at one of the junior editor’s 
parents’ apartment in the Dakota, in which art-hung room bled into art-hung room.

Answer

No in this context it means overflowed into.

Answer

By the act of blending into each other they formed a uniform mixture ,so there was no perceptible separation between the one room and the other .It is figurative language here !