In Czechia and Slovakia we have mapy.cz which gives you more detailed map for walking/hiking, including contour lines. See [^1] for example.
The coloured trails you can see at more detailed zoom levels, are part of the hiking trail system. The outdoor signage even has a national technical norm [^2] (in Slovak, but has some terminology translated int to English and German).
This is just OpenStreetMap with another frontend on top, you can see this by going to the area[1] and going to the right, selecting layers and looking at the CyclOSM one.
Also, a bit lame that on mapy.cz, you have to click on the "and others" to actually see the OpenStreetMap credit.
Surely there's nothing wrong with using OSM as one of your primary map data sources? As far as I know, Mapy.cz uses several sources in the Czechoslovak territory, although abroad, perhaps quite a bit fewer of them are being used.
The coloured trails you can see at more detailed zoom levels, are part of the hiking trail system. The outdoor signage even has a national technical norm [^2] (in Slovak, but has some terminology translated int to English and German).
[1] https://en.mapy.cz/turisticka?x=19.8702765&y=48.7675046&z=14 [2] http://www.jazdecka-turistika.sk/images/stories/dokumenty/KT...