Assigning different wire or halo materials to different parts of a mesh This is a follow-up question to Stephen's Add different materials to different parts of a mesh? As explained there, it is possible to assign different surface materials to different faces of a mesh.  However, the same method does not seem to work when the materials involved are not surface materials.
For example, suppose a cube mesh has two materials and both are wire materials.  If I assign the second material to everything (enter the Edit Mode, select all vertices [A], select the second material in the Properties panel > Materials tab, and click the Assign button), the cube is still rendered with the first material.  I have the same problem with two halo materials.

How do you assign different wire materials to different edges of a mesh? How do you assign different halo materials to different vertices of a mesh?
It's not possible, you can only use a single wire or halo material and this will be applied to the entire mesh.

Part of the reason is that materials are set per face, and wires and halos are for edges and vertices so there is no exact way to map them. But it's mostly just something that was never implemented.