Hello,
I created svg export tool which does respect per-net coloring.
pcbnew allow per-net coloring so it would be nice if kicad-cli could use them. Maybe some day it will, until then there is https://github.com/adamws/kicad-svg-extras.
There is also css styling option which could be used for some simple websites, for example: KiCad SVG Extras - Interactive Net Highlighting Demo - I focused on nets right now, maybe I will add footprints outlines later (something similar to InteractiveHtmlBom).
Anyway, maybe some of you will find this useful.