Very nicely done! I like the colour you chose for the deck. Just one small point- the German flag you have used was adopted by the Weimar Republic in 1919, after Markgraf was scuttled. The Imperial flag is correct and was (from top) Black, White and Red. In the case of a naval ship, this flag would be a 'Jack', which would have a Iron Cross in the centre: http://flagspot.net/flags/de1871~j.html
The Imperial Naval 'war' ensign would have been flown, a picture of which can be found in the link here http://flagspot.net/flags/de1871~w.html
Finally, this link shows the ensign and jack very clearly. http://www.fotolibra.com/gallery/771007/battleship-kaiser-wwi-german-navy/
My (unbuilt) version of this kit includes the correct flag decals, and also an iron cross to be attached to the bow- I've not seen photographic evidence of the latter, but I trust ICM that it is correct?
Will