We establish a simple generalization of a known result in the plane. The
simplices in any pure simplicial complex in R^d may be colored with d+1 colors
so that no two simplices that share a (d-1)-facet have the same color. In R^2
this says that any planar map all of whose faces are triangles may be
3-colored, and in R^3 it says that tetrahedra in a collection may be "solid
4-colored" so that no two glued face-to-face receive the same color.Comment: 11 pages, 6 figure
