Plots[int index]

// Initialize method of a custom indicator
protected override void Initialize()
{

    // Lines are added to the Lines collection in order
    Add(new Plot(Color.Orange, "Plot1")); // Stored in Plots[0]
    Add(new Plot(Color.Blue, "Plot2"));   // Stored in Plots[1]
}

// Dynamically change the primary plot's color based on the indicator value

protected override void OnBarUpdate()

{

    if (Value[0] > 70)

         Plots[0].Pen = new Pen(Color.Blue);

    else

         Plots[0].Pen = new Pen(Color.Red);

}