Halston designer 3 button plaid blazer jacket

Halston designer 3 button plaid blazer jacket size 10 petite. I am having a hard time getting the lighting to give me the most accurate color of this jacket but It is almost a greenish gray brown color. See last photo of the back which I noticed end while taking measurements. It seems more like the treading itself. It is at the bottom along the middle seam on the back.