Several popular application support vertex colors in wavefront OBJ files. This isn't part of the original format, but it's now a de facto standard. Add support for vertex colors to interface's OBJ reader.
This work would primarily be in libraries/fbx/src/OBJReader.cpp -- look for the comment: "// the spec(s) get(s) vague here. might be w, might be a color... chop it off." There may also be some work in relaying the color to the rest of the system.