If you want change the color of lines in a dvt:lineChart because you don’t like the default colors of each chartDataItem. You can use a chartSeriesStyle inside seriesStamp.
I show a example below
<dvt:lineChart id="lc1" var="row" value="#{bindings.vo.collectionModel}"
contentDelivery="immediate" styleClass="AFStretchWidth" zoomAndScroll="live"
dataSelection="single" title="demo">
<f:facet name="dataStamp">
<af:group id="g1">
<dvt:chartDataItem id="di1" value="#{row.value1}" group="#{row.group}" series="custom1"/>
<dvt:chartDataItem id="di2" value="#{row.value2}" group="#{row.group}" series="custom2" />
</af:group>
</f:facet>
<f:facet name="seriesStamp">
<af:group id="g2">
<dvt:chartSeriesStyle id="css2" series="custom1" color="#ff2121" lineStyle="solid" />
<dvt:chartSeriesStyle id="css3" series="custom2" color="#f2c779" lineStyle="solid"/>
</af:group>
</f:facet>
</dvt:lineChart>
