backgroundcolor — Declare the background color that should be used in the ReST
applications when referencing this package.
If the backgroundcolor element appears in an
application's attributes then the declared color will be used instead of the
default background color for applications referencing this package. The color
should be given in hex notation as would be given in HTML code.
The following elements are valid parents of backgroundcolor:
explorerattributes, installerattributes, monitorattributes.