Changing materials on different array parts

Hello Blender Artists!

I’ve got a fairly straight forward question. How do I change the materials on different “parts” of an array?
Really all I have to do is change the diffuse color, I don’t know if that makes it any easier but just for your information that’s the only thing I need to do. I kinda need it to look like on this building.
https://www.google.se/search?q=ting+1&source=lnms&tbm=isch&sa=X&ei=ZQmzU_XuBbTF4QTh7YGwCw&sqi=2&ved=0CAYQ_AUoAQ&biw=1680&bih=916

http://www.google.se/imgres?imgurl=http%3A%2F%2Fsverigesradio.se%2Fdiverse%2Fappdata%2Fisidor%2Fimages%2Fnews_images%2F110%2F3039172_570_321.jpg&imgrefurl=http%3A%2F%2Fsverigesradio.se%2Fsida%2Fartikel.aspx%3Fprogramid%3D110%26artikel%3D5681995&h=321&w=570&tbnid=joZ-B1BOWLb5eM%3A&zoom=1&docid=zpIRy7098V6SOM&ei=6v6yU-HtLPLR4QS5zoCYDA&tbm=isch&ved=0CC0QMygOMA4&iact=rc&uact=3&dur=1199&page=1&start=0&ndsp=32

Thank you all in advance!

I don’t believe it can be done with an array. My two suggestions would be:

  1. Apply the array, create a new material mat2. Tab into edit mode, select a vert from each mesh you want to change, ctrl-L to selected connected, and in the material tab click apply.

  2. Use a non random particle system, emitting from vertices instead of the array.