I just figured out that combing markerclusters with layers in #SPARQL queries visualising results from #Wikidata on maps can give you a nice coloured classification of periodicals by publishing language.
Unfortunately the query is too long for posting it here ...
Update: created a gist for this query at https://gist.github.com/tillgrallert/3999b5da1616107a483221bc04a420c2