What's the rarer colour from these 3

[HK1837]

I have 11 x HZ in Carribean Turquoise, 21 x HZ in Atlantis Blue and 3 x HZ in Mistral Grey. You have to remember though some HZ colours will be rarer than others due to the timeframe they were available. For example Mistral Grey wasn't available until around 11/78. If you want a really rare HZ colour use Ultra Blue, I have nothing recorded in this colour, and it was only available unto the end of July 1978. I have only ever seen a couple of HZ GTS's in that colour and my Overlander was also that colour originally. A few other very rare HZ colours (on Sandman anyway) are:

Dynasty Gold;
Antelope;
Persian Sand MkII;
Mojave Beige;
Mirage Blue;
Ashley Grey;
Sandlewood.