Direct support for GeoJSON properties such as marker-color, marker-size, marker-symbol, stroke, stroke-width, stroke-opacity.
Settable for stroke (but not from GeoJSON directly).
.Style(style => style.Stroke(stroke => stroke.Width(4).Color("#3f51b5")).Opacity(1))
Not settable for Marker (point) either way.
Properties setting options for color, style, etc. should be directly from the source. When setting values from other types of datasources, setting options should be possible (as in Stroke) for other elements such as Markers.
Additional element types could be supported directly (lines), but easier to use the standard.