Abies procera (common name noble fir) is native to western USA with hardiness rating of 5-6.
Abies procera ‘Glauca’
I believe the few blue firs that I acquired from Hortico many years ago are Abies procera ‘Glauca’. Only one of them left, but in very bad shape due to neglect and overcrowding. It does not have a neat growing habit and is somewhat irregular upright.
Abies procera ‘Sherwoodii’
The Abies procera ‘Sherwoodii’ shown in books and at Whistling Gardens are very attractive with creamy yellow needles. The plant I have is a baby and need a few more years to look presentable.
This cultivar is a chance seedling from Sherwood Nursery in USA.