I can tell you the percent values used in the attached screenshot are much higher than 200% and 150%. I applied those values to the code and y0u can see from the screenshot I have attached below that the range is far from what you have specified.
It's also very important to note the shaded areas on the screenshot you provided are not the same size. Check that more closely and you will see for yourself. So your attempt to replicate this chart study you found is far from meeting the mark. The range that is shaded red on the screenshot you provided is being computed using an entirely different formula than you supposed.
But here is the code that you have specified, even though it does not match the screenshot you provided as an example:
input percentThresholdTop = 200.0;
input percentThresholdBottom = 150.0;
input timeFrame = AggregationPeriod.DAY;
DefineGlobalColor("shading", Color.RED);
def previousDayClose = close(period = timeFrame)[1];
plot rangeTop = previousDayClose + (previousDayClose * percentThresholdTop * 0.01);
rangeTop.SetPaintingStrategy(PaintingStrategy.HORIZONTAL);
rangeTop.AssignValueColor(GlobalColor("shading"));
plot rangeBottom = previousDayClose + (previousDayClose * percentThresholdBottom * 0.01);
rangeBottom.SetPaintingStrategy(PaintingStrategy.HORIZONTAL);
rangeBottom.AssignValueColor(GlobalColor("shading"));
AddCloud(rangeTop, rangeBottom, GlobalColor("shading"), GlobalColor("shading"));