By James Philip
The solution to this problem is to open the Phasing dialogue box, select the Graphic Overrides tab and in the Material Column, by new material, overwrite Phase – New with By Category and the Wall material will appear as normal and you can use the overrides to alter its appearance. i.e. add colour and lineweight. See Figs 2 & 3.
The final Result is as shown. See Fig 4.