凡例は手動で構築でき、マーカーをカスタマイズできます。

ScottPlot.Plot myPlot = new();

myPlot.Add.Signal(Generate.Sin(51));
myPlot.Add.Signal(Generate.Cos(51));
myPlot.Legend.IsVisible = true;

LegendItem item1 = new()
{
    LineColor = Colors.Magenta,
    MarkerFillColor = Colors.Magenta,
    MarkerLineColor = Colors.Magenta,
    MarkerShape = MarkerShape.Cross,
    LineWidth = 2,
    LabelText = "Alpha"
};

LegendItem item2 = new()
{
    LineColor = Colors.Green,
    MarkerFillColor = Colors.Green,
    MarkerLineColor = Colors.Green,
    LineWidth = 4,
    LabelText = "Beta"
};

LegendItem[] items = { item1, item2 };
myPlot.ShowLegend(items);

myPlot.SavePng("demo.png", 400, 300);