It takes a little more effort to get county level images for the UK...
GeoGraphics[({GeoStyling[Once[countryColor[#1]]], #1[ "Polygon"]} & ) /@
Flatten[(#1["Subdivisions"] & ) /@
Entity["Country", "UnitedKingdom"]["AdministrativeDivisions"]] /.
{RGBColor[_ImageMeasurements] :> None, {_, _Missing} :> Nothing},
GeoBackground -> None]
![enter image description here](https://community.wolfram.com//c/portal/getImageAttachment?filename=UK.png&userId=21415)