- * <listitem><para>a standard name (taken from the X11 rgb.txt
- * file");</para></listitem>
- * <listitem><para>an hexadecimal value in the form: '#rgb', '#rrggbb',
- * '#rgba' or '#rrggbbaa';</para></listitem>
- * <listitem><para>a RGB color in the form 'rgb(r, g, b)';</para></listitem>
- * <listitem><para>a RGBA color in the form 'rgba(r, g, b,
- * a)';</para></listitem>
+ * <listitem>
+ * <para>a standard name (as taken from the X11 rgb.txt file)</para>
+ * </listitem>
+ * <listitem>
+ * <para>an hexadecimal value in the form: <literal>#rgb</literal>,
+ * <literal>#rrggbb</literal>, <literal>#rgba</literal> or
+ * <literal>#rrggbbaa</literal></para>
+ * </listitem>
+ * <listitem>
+ * <para>a RGB color in the form: <literal>rgb(r, g, b)</literal></para>
+ * </listitem>
+ * <listitem>
+ * <para>a RGB color in the form: <literal>rgba(r, g, b, a)</literal></para>
+ * </listitem>
+ * <listitem>
+ * <para>a HSL color in the form: <literal>hsl(h, s, l)</literal></para>
+ * </listitem>
+ * <litsitem>
+ * <para>a HSL color in the form: <literal>hsla(h, s, l, a)</literal></para>
+ * </listitem>