Blank map of Austria displaying all municipalities.
The municipalities can be simply colored using style sheets like:
".gkz10101 { fill:#b80062;fill-opacity:1 }"

For an example on how to use this, you can look at File:COVID-Austria - new Infections per 100k per district.svg which uses the same layout, just at a district level.
Own work, SVG based on TopoJSON from Austrian Open Data Portal, Github, CC BY 4.0, Flooh Perlot CC-BY 4.0, Original file: CC BY 3.0 Geoland Kärnten. SVG created using [mapshaper.org mapshaper]
Colazivi