public enum VoxelVariableDataType : System.Enum, System.IComparable, System.IConvertible, System.IFormattable, System.ISpanFormattable  

{
  var variable = voxelLayer.GetVariableProfiles().First();
  var renderer = variable.Renderer;
  if (variable.DataType == VoxelVariableDataType.Continuous)
  {
    //Renderer will be stretch
    var stretchRenderer = renderer as CIMVoxelStretchRenderer;
    //access the renderer

  }
  else //VoxelVariableDataType.Discrete
  {
    //Renderer will be unique value
    var uvr = renderer as CIMVoxelUniqueValueRenderer;
    //access the renderer
  }
}

{
  //Get the variable profile on which to access the data
  var variable = voxelLayer.SelectedVariableProfile;
  //or use ...voxelLayer.GetVariableProfiles()

  //Data range
  var min = variable.Statistics.MinimumValue;
  var max = variable.Statistics.MaximumValue;

  //Color range (Continuous only)
  double color_min, color_max;
  if (variable.DataType == VoxelVariableDataType.Continuous)
  {
    var renderer = variable.Renderer as CIMVoxelStretchRenderer;
    color_min = renderer.ColorRangeMin;
    color_max = renderer.ColorRangeMax;
  }
}