CloudAttribute

using cAlgo.API;
using cAlgo.API.Indicators;

namespace cAlgo
{
    // This indicator fills the area between two outputs with the Clouds entry of config.json
    public partial class BollingerBandsCloudSample : Indicator
    {
        private BollingerBands _bollingerBands;

        protected override void Initialize()
        {
            _bollingerBands = Indicators.BollingerBands(Bars.ClosePrices, Periods, 2, MovingAverageType.Simple);
        }

        public override void Calculate(int index)
        {
            Top[index] = _bollingerBands.Top[index];
            Bottom[index] = _bollingerBands.Bottom[index];
        }
    }
}

class BollingerBandsCloudSample():
    def initialize(self):
        self.bollingerBands = api.Indicators.BollingerBands(api.Bars.ClosePrices, api.Periods, 2, MovingAverageType.Simple)

    def calculate(self, index):
        api.Top[index] = self.bollingerBands.Top[index]
        api.Bottom[index] = self.bollingerBands.Bottom[index]

{
  "AccessRights": "None",
  "TimeZone": "UTC",
  "IsOverlay": true,
  "Parameters": [
    {
      "Name": "Periods",
      "Type": "Integer",
      "DefaultValue": 20,
      "MinValue": 2
    }
  ],
  "LineOutputs": [
    {
      "Name": "Top",
      "Color": "Red"
    },
    {
      "Name": "Bottom",
      "Color": "Red"
    }
  ],
  "Clouds": [
    {
      "FirstLineName": "Top",
      "SecondLineName": "Bottom",
      "Opacity": 0.2
    }
  ]
}