public abstract class CIMColorRamp : CIMObject, System.ComponentModel.INotifyPropertyChanged, System.Xml.Serialization.IXmlSerializable  

public async Task ApplyColorRampAsync(FeatureLayer featureLayer, List<string> fields)
{

    StyleProjectItem style =
        Project.Current.GetItems<StyleProjectItem>()
            .FirstOrDefault(s => s.Name == "ColorBrewer Schemes (RGB)");
    if (style == null) return;
    var colorRampList = await QueuedTask.Run(() => 
                style.SearchColorRamps("Red-Gray (10 Classes)"));
    if (colorRampList == null || colorRampList.Count == 0) return;
    CIMColorRamp cimColorRamp = null;
    CIMRenderer renderer = null;
    await QueuedTask.Run(() =>
    {
        cimColorRamp = colorRampList[0].ColorRamp;
        var rendererDef = new UniqueValueRendererDefinition(fields, null, cimColorRamp);
        renderer = featureLayer?.CreateRenderer(rendererDef);
        featureLayer?.SetRenderer(renderer);
    });

}

//Must be called on the MCT
//var pcsl = ...;

//At 2.x - var fields = pcsl.QueryAvailablePointCloudRendererFields(
//                           PointCloudRendererType.StretchRenderer);

var fields = pcsl.GetAvailablePointCloudRendererFields(
                         PointCloudRendererType.StretchRenderer);
var stretchDef = new PointCloudRendererDefinition(
                          PointCloudRendererType.StretchRenderer)
{
  //Will be either ELEVATION or INTENSITY
  Field = fields[0]
};
//Create the CIM Renderer
var stretchRenderer = pcsl.CreateRenderer(stretchDef) 
                                   as CIMPointCloudStretchRenderer;
//Apply a color ramp
var style = Project.Current.GetItems<StyleProjectItem>()
                                .First(s => s.Name == "ArcGIS Colors");
var colorRamp = style.SearchColorRamps("").First();
stretchRenderer.ColorRamp = colorRamp.ColorRamp;
//Apply modulation
stretchRenderer.ColorModulation = new CIMColorModulationInfo()
{
  MinValue = 0,
  MaxValue = 100
};
//apply the renderer
pcsl.SetRenderer(stretchRenderer);