Change or create BEX_THEME

Dear Friends,

I created a web report in WAD 7.0 and add the command to export the template in Excel.

I can chose only the following themes In the command button parameters theme (BEX_THEME):

- SAP standard (DISPLAY)

- Black and White (BACLKWHITE)

Can you tell me if you can modify these styles or to add another one custom?

Any help will be highly appricated.

Regards

Naeem