Solution that would be nice its additional field "crosshairMarkerColor" to addLineSeries settings

const lineSeries = chart.addLineSeries({
    crosshairMarkerVisible: true,
    crosshairMarkerRadius: 6,
    crosshairMarkerColor: '#111',
});

When plotting with gnuplot on windows, Helvetica is not available by default. Would it be ok to use alternative on Windows?

.\example_plot_1.exe

(process:23384): Pango-WARNING **: 17:16:06.198: couldn't load font "Helvetica Not-Rotated 200", falling back to "Sans Not-Rotated 200", expect ugly output.