After less than 6 moths I'm back in Black. While OP White Unicorn was fairly easy, the white 3rd party housing was crap. It still is white, so no color changes. Just to list the reasons:

• Cracks all over left an right side
• different measures, so lot of tension all the time (hence the cracks)
• Display kept popping out of the housing for about 0,5mm all the time

Going back to my (still ok just scratchy) black OEM housing was not as easy though. Due to the slightly different meassuers getting the display out abain was a true pain in the *****. The N9 still works after a solid 2.5 y of usage and two housing swaps The white one went straight to the bin anyways...