</a></dt>
<dd><p>A named list of vectors specifying how to style the sf
overlay. Possible names are "stroke", "stroke-width" (or "stroke_width"),
"stroke-opacity" (or "stroke_opacity"), "fill", and "fill-opacity" (or
"fill_opacity"). The fill and stroke color values can be specified as
six-digit hex codes or color names, and the opacity and width values should
be supplied as floating-point numbers. If overlay_style is <code>NULL</code>, the
style values can be pulled from columns with the same names in
<cod