Ultraviolet-visible spectra are presented for a polycrystalline sample of chlorine clathrate hydrate and two single crystal samples of bromine clathrate hydrate. The data shows that the UV-visible spectroscopy is a sensitive probe for studying the interactions between the halogen guest molecule and the host water lattice. The spectrum for chlorine hydrate shows a surprisingly strong temperature dependence. The spectra reported for bromine clathrate hydrate single crystals reinforce our previous conclusion that there is a stable cubic type II structure as well as the tetragonal structure. There is also a metastable cubic type I structure. The new results are discussed in the context of previous results, resonance Raman spectroscopy, and how the molecules fit into the host cages.