XML source

...
<scene>
  <FX>General Road Building noises.</FX>
  <speech speaker="Prosser">
    Come off it Mr Dent, you can't win
    you know. There's no point in lying
    down in the path of progress.
  </speech>
  <speech speaker="Arthur">
    I've gone off the idea of progress.
    It's overrated
  </speech>
...

XSLT stylesheet

...
<xsl:template match="FX">
  <fo:block font-weight="bold">
    <xsl:apply-templates/>
  </fo:block>
</xsl:template>

<xsl:template match="speech[@speaker='Arthur']">
  <fo:block background-color="blue">
    <xsl:value-of select="@speaker">:
    <xsl:apply-templates/>
  </fo:block>
</xsl:template>
...

Result