Map each distinct value of the node color channel's driver to the
color the encoding assigns it, in data insertion order (the same
order makeColorResolver consumes palette slots). Useful for keeping
auxiliary UI (legends, the FacetFilter swatches) consistent with the
canvas. Returns an empty map for non-categorical color channels.
Map each distinct value of the node color channel's driver to the color the encoding assigns it, in data insertion order (the same order makeColorResolver consumes palette slots). Useful for keeping auxiliary UI (legends, the FacetFilter swatches) consistent with the canvas. Returns an empty map for non-categorical color channels.