Translating color code in pdf

Hello all
I am still strying to convert colors from my asciidoctor files into pdf's. See previous thread.
I am now trying the asciidoctor-fopub route without any success so far.
I have the following basic test.adoc file:

This should be [red]#printed in red#

Which is translated into the following xml:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<?asciidoc-toc?>
<?asciidoc-numbered?>
<book lang="en">
<bookinfo>
<title>Untitled</title>
<date>2016-02-29</date>
</bookinfo>
<preface>
<title></title>
<simpara>This should be <phrase role="red">printed in red</phrase></simpara>
</preface>
</book>

Now I have edited the fo-pdf.xsl file in asciidoctor-fopub/build/fopub/docbook-xsl/ and I added:

...
<xsl:template match="processing-instruction('asciidoc-pagebreak')">
    <fo:block break-after='page'/>
  </xsl:template>

<xsl:template match="phrase[@role='red']">
  <fo:inline color="red">
    <xsl:apply-templates/>
  </fo:inline>
</xsl:template>
...

I then run fopub text.xml but my pdf still does not show the red color.
What am I doing wrong ? I must confess I am not an xslt expert :-)
Jacques

Thanks Dan. Your suggestion did the trick. I also tried your xsl:choose option. The following code works ok. Is that what you had in mind ?

<xsl:template match="db:phrase">
  <xsl:choose>
    <xsl:when test="@role='blue'">
      <fo:inline color="rgb(0,255,0)">
      <xsl:apply-templates/>
      </fo:inline>
    </xsl:when> 
    <xsl:when test="@role='red'">
      <fo:inline color="rgb(255,0,0)">
      <xsl:apply-templates/>
      </fo:inline>
    </xsl:when> 
    <xsl:when test="@role='gray'">
      <fo:inline color="rgb(128,128,128)">
      <xsl:apply-templates/>
      </fo:inline>
    </xsl:when> 
  </xsl:choose>
</xsl:template>

Also should not that type of code for the usual colors be included in the asciidoctor specific part of fo-pdf.xsl ?
Cheers
Jacques