Unfortunately the background is specified in several places in the macro
files.

If you're runnning UNIX/Linux going into the macros directory and doing
a "grep bgcolor *.dm" should find all of them. On my local install,
bgcolor is specified in: base.dm, collect.dm, html.dm, status.dm,
style.dm, translang.dm and users.dm

Sometimes the bgcolor is specified several times in a single file.
Unfortunately to change the bgcolor across the whole website, all of
these must be changed.

stuart