Hi Deon,
As Oisín told you, ~webgui_new_design is not needed. It is only valid for Netweaver 7.00 and 7.01, with kernel 7.20, 7.21 or 7.22. As of Netweaver 7.02, the new design is the standard.
You can try appending the URL with &sap-theme=sap_bluecrystal. I just tested in my test system (SAP_BASIS 7.40, with kernel 7.42 pl 412) and it works, i.e. the theme used is bluecrystal.
You can also read KBA 1508958.
Kind regards,
Cris
PS: Example:
Using the default (Corbu theme):
Appending the URL:
