The link you provided is for the old RadChart. Your question concerns the new ChartView (this is a set of controls - RadCartesianChart, RadPieChart, RadPolarChart). The new chart does not have such a functionality built in. The line is not drawn with different segments as this will decrease performance. The line is a single Path element and it has a Stroke property.
We have not planned this feature for the new ChartView control because we are not sure that it would bring value into perceiving data. Can you send us some pictures demonstrating the results you are after so that we see if we should consider such finctionality for a future release. Currently you can use the PointTemplate property and have custom visuals (point marks) in different color depending on the data item.
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