I checked the relation "A Mátra bércein", however it does not specify anything red, maybe it's a default on your renderer: https://www.openstreetmap.org/relation/5563755

I have added colour=blue in an attempt to specify this. Sadly, I could not add the machine-parseable osmc:symbol tag as it is too complex.

I'm closing this note as I think there is nothing else left to do. If you still find this way red, please file an issue for your map application or reopen this note.