I'm not so sure the "Thistle heather" color is actually gray. I think it's more like a grayish purple/eggplant. On my monitor the full zip shak in Thistle looks clearly grayish purple:
http://www.ibexwear.com/shop/Product...=Shak-Full-Zip
Might go well with your grey pieces anyway though.
Anyone have a 'thistle heather" piece and can let us know?
Hope your shak fits well when it arrives!