I just checked. It's hamwb.lha on Aminet.
Run Workbench in 4096 or 262144 colors.
speed would depend on your setup.
Does anyone have any experience with using this on 3.1? I had been using the Rebel16 palette and tried to switch to Ham6 laced using HamWB but it has just messed all my colours up.
The wallpaper looks worse than the 16 colour version. How is this supposed to be used?