public static IList<ColorRampStyleItem> SearchColorRamps( 
   StyleProjectItem styleProjectItem,
   string searchString
)

{
    //StyleProjectItem can be "ColorBrewer Schemes (RGB)", "ArcGIS 2D"...
    //Search for color ramps
    //Color Ramp searchString can be "Spectral (7 Classes)", "Pastel 1 (3 Classes)", "Red-Gray (10 Classes)"..
    styleProjectItem.SearchColorRamps("searchString");
}

{
    List<string> fields = new List<string>() { "Field1" };
    //Note: Needs QueuedTask to run
    StyleProjectItem styleToUse =
      Project.Current.GetItems<StyleProjectItem>()
          .FirstOrDefault(s => s.Name == "ColorBrewer Schemes (RGB)");
    if (style == null) return;
    //Note: Needs QueuedTask to run
    var colorRampListFound = styleToUse.SearchColorRamps("Red-Gray (10 Classes)");
    if (colorRampListFound == null || colorRampListFound.Count == 0) return;
    CIMColorRamp cimColorRamp = null;
    CIMRenderer renderer = null;

    cimColorRamp = colorRampListFound[0].ColorRamp;
    var rendererDef = new UniqueValueRendererDefinition(fields, null, cimColorRamp);
    renderer = featureLayer?.CreateRenderer(rendererDef);
    featureLayer?.SetRenderer(renderer);
}

{
    string colorBrewerSchemesName = "ColorBrewer Schemes (RGB)";
    StyleProjectItem colorBrewerStyle = Project.Current.GetItems<StyleProjectItem>().First(s => s.Name == colorBrewerSchemesName);
    string colorRampName = "Greens (Continuous)";
    //Note: Needs QueuedTask to run
    IList<ColorRampStyleItem> colorRampListFromTheStyle = colorBrewerStyle.SearchColorRamps(colorRampName);

    ColorRampStyleItem colorRampFound = colorRampList[0];
    GraduatedColorsRendererDefinition gcDef = new GraduatedColorsRendererDefinition()
    {
        ClassificationField = "CROP_ACR07",
        ClassificationMethod = ArcGIS.Core.CIM.ClassificationMethod.NaturalBreaks,
        BreakCount = 6,
        ColorRamp = colorRampFound.ColorRamp,
        SymbolTemplate = SymbolFactory.Instance.ConstructPolygonSymbol(
                              ColorFactory.Instance.GreenRGB, SimpleFillStyle.Solid, null).MakeSymbolReference(),
        ExclusionClause = "CROP_ACR07 = -99",
        ExclusionSymbol = SymbolFactory.Instance.ConstructPolygonSymbol(
                              ColorFactory.Instance.RedRGB, SimpleFillStyle.Solid, null).MakeSymbolReference(),
        ExclusionLabel = "No yield",
    };
    var featureLayerCreationParams = new FeatureLayerCreationParams((new Uri(@"c:\Data\CountyData.gdb\Counties")))
    {
        Name = "Crop",
        RendererDefinition = gcDef
    };
    //Note: Needs QueuedTask to run
    LayerFactory.Instance.CreateLayer<FeatureLayer>(featureLayerCreationParams, MapView.Active.Map);
}

{
  // Note: call within QueuedTask.Run()
  {
    var fields = pointCloudSceneLayer.GetAvailablePointCloudRendererFields(
                            PointCloudRendererType.StretchRenderer);
    var stretchDef = new PointCloudRendererDefinition(
                              PointCloudRendererType.StretchRenderer)
    {
      //Will be either ELEVATION or INTENSITY
      Field = fields[0]
    };
    //Create the CIM Renderer
    var stretchRenderer = pointCloudSceneLayer.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
    pointCloudSceneLayer.SetRenderer(stretchRenderer);
  }
}