The light blue markers are where DeBeers mines their diamonds. The yellow markers are the cutting and polishing centers that DeBeers sends their diamonds to. The purple makers are the biggest DeBeers Jewelers in the world. The darker blue marker is London which is a cutting and polishing center, a DeBeers Jeweler, and the headquarters of the company. As you can see everything is interconnected and that why DeBeers is the largest seller of diamonds in the world.