mark a railway line from point A to point B in red colour

In the layer «traffic map» I would like to mark a railway line from city A to city B in red colour, for example. Is there a way to do this?
I could draw a straight line, but of course, it looks much more professional if the red line would follow the line of the railway.

I’ve found this service:,18.627341;54.345856,18.365009 - could it be helpful for you?

Another routing service for railways:,18.535266,54.440299,18.561401#12/54.5076/18.5353, but here sometimes is hard to set route between points. Probably OSM data is faulty in some places.

Also brouter has possibility to route railways and it is very easy to use:,54.381776;18.20602,54.333874&profile=rail

I hope that something will be good for you.

Hello Marek
Thank you very much for your great support. I will try to draw a proper map.