public Form1()
{
    InitializeComponent();

    var sig1 = formsPlot1.Plot.Add.Signal(Generate.Sin());
    sig1.LegendText = "Sin";
    var sig2 = formsPlot1.Plot.Add.Signal(Generate.Cos());
    sig2.LegendText = "Cos";

    // apply custom styling options
    formsPlot1.Plot.Legend.BackgroundColor = Colors.Magenta;
    formsPlot1.Plot.Legend.FontColor = Colors.White;

    // prepare the two styles we will be switching between later
    PlotStyle lightStyle = new ScottPlot.PlotStyles.Light();

    // the WinForms control customizes light style by setting background to match the form
    lightStyle.FigureBackground = ScottPlot.Color.FromColor(SystemColors.Control);

    PlotStyle darkStyle = new ScottPlot.PlotStyles.Dark();
    PlotStyle customStyle = formsPlot1.Plot.GetStyle().WhereDifferentFrom(lightStyle);

    checkBox1.CheckedChanged += (s, e) =>
    {
        // apply light or dark mode
        if (checkBox1.Checked)
            formsPlot1.Plot.SetStyle(darkStyle);
        else
            formsPlot1.Plot.SetStyle(lightStyle);

        // apply the customized style options
        formsPlot1.Plot.SetStyle(customStyle);

        formsPlot1.Refresh();
    };
}