DB2LaTeX are a set of XSLT stylesheets which generate high level LaTeX2e from your docbook document. They do not perform any FO transformation, the only thing they do is to map DocBook tags into more or less standard LaTeX (a recent installation of LaTeX 2e is required, with most common packages. However, in more stable releases, package dependencies will be completely managed with xsl variables, making it virtually compatible with basic LaTeX 2e installations). All the "styling" has to be done by modifying available xsl:variables, overriding and customizing templates, and in the last, by adding your "sty" files.