As far as I'm aware they are the only ones operating the (KC) and not DC10 as you rightly point out. The roundel is as you say a pie chart of red white and blue. I think that every other AF in Europe use A330 or A300 or B767 as tanker/logistic aircraft. I seem to remember that they were ex-KLM or Martinair ships and with the mass of engineering knowledge and spares available the Dutch government bought them for airforce usage tanking and troop moving, especially UN Dutch deployments overseas.
SHJ