fluxbox package is included in 2.1(Asumi) RC1 or later.

A focus problem is known, if used with old versions of kinput2, mozilla, and/or galeon. Update these from RC1 or later distribution.

It is the current specification. Original source contains "bsetroot" manual. In Momonga Linux that "bsetroot" is renamed as "fsetroot" to let it coexist with "bsetroot" contained in Blackbox.