Convert a point cloud renderer definition to a CIMPointCloudRenderer using the PointCloudSceneLayer.CreateRenderer method.
Use PointCloudSceneLayer.GetAvailablePointCloudRendererFields to check whether or not a point cloud layer contains (one of) the necessary field(s) to support the given renderer. There are up to five fields that could be available for rendering depending on the given layer:
1. ELEVATION: can be used with Stretch and ClassBreaks
2. CLASS_CODE: LAS classification codes, can be used with Unique Value
3. RETURNS: Lidar pulse return number, can be used with Unique Value
4. RGB: can be used with RGB
5. INTENSITY: can be used with Stretch and ClassBreaks

Reference

PointCloudRendererDefinition Members
ArcGIS.Desktop.Mapping Namespace