It is important mathematically (in particular, geometrically) to study Coxeter groups. We investigate Coxeter groups and obtain topological properties for boundaries of metric spaces of non-positive curvature and hyperbolic spaces on whose Coxeter groups are geometrically acted. Specifically, we provide the following results: a necessary and sufficient condition with a topological fractal structure of its boundary, the construction of topological universal spaces as the boundaries of Coxeter groups, and, an extension of the decomposition theorem to the Coxeter group. Moreover, we investigate colorings numbers of maps deeply related to fix points of remainders of compactifications and we obtain a necessary and sufficient condition with colorings numbers of homeomorphisms on locally finite graphs