Hi there.
I would like to use OSM maps with highlighted suburbs borders. I just cannot manage to highlight more than 1 suburb at a time.
For example: http://www.openstreetmap.org/relation/2553582 and www.openstreetmap.org/relation/2553489
How to highlight both or all suburbs like this in a city? Is that even possible?
Thank you very much.
You write your own rendering software, or rather you adapt the code of the existing software for your purposes.
OSM is the underlying data, not the rendered image. The rendered versions are on the web site to assist in maintaining the underlying data and to demonstrate what can be done with that data. The ability to highlight a single object is really only there for the former purpose.
You might want to have a look at the recent threads on colouring US counties, as the administrative areas tool mentioned by Wambacher may be a s useful starting point in extracting the necessary outlines to feed into your tool.
(You could also try to see if someone has already written a tool to do this.)
Are you looking for something like https://osm.wno-edv-service.de/boundaries/ ?
Choose any country or sub-region from the left-side tree menu.
I think that you cannot use the main map view in openstreetmap.org to show more than one such element.
Maybe you can try http://wiki.openstreetmap.org/wiki/UMap ?
So what map display service do you want to use alternatively?
http://leafletjs.com/ or http://openlayers.org/ are the two most popular in the OSM universe.
Yes! This is what I was searching for. Thank you very much, I think it will perfectly serve my needs 
@hadw, thank you too for the explanation.