Trying to create a simple line symbol. But getting an error: "The type 'ESRI.ArcGIS.Display.RgbColorClass' has no constructors defined"
public override void OnClick()
{
IDocument pdoc = m_application.Document;
IMxDocument pmxdoc = (IMxDocument)pdoc;
IActiveView pactive = pmxdoc.ActiveView;
IRgbColor rgbColorCls = new RgbColorClass();
rgbColorCls.Red = 138;
rgbColorCls.Green = 151;
rgbColorCls.Blue = 255;
ISimpleLineSymbol simpleLineSymbol = new SimpleLineSymbol();
simpleLineSymbol.Color = rgbColorCls;
}