  We continue the study of open associahedra associated with bi-color
scattering amplitudes initiated in arXiv:1912.08307. We focus on the facet
geometries of the open associahedra, uncovering many new phenomena such as
fiber-product geometries. We then provide novel recursion procedures for
calculating the canonical form of open associahedra, generalizing recursion
relations for bounded polytopes to unbounded polytopes.
