Years ago, 80's, I picked several cotton Garand slings.  One was dyed black so I tossed it in the drawer and forgot about it.  Today I decided just to put it on my retro a1 since al my green ones are in use.  Did they ever dye these?  (It's not a 601 I got schooled on that).

The early  SP1 slings were  black canvas.  The first type, just like the 601 sling, the second type, just like a canvas garand sling, but black.  There were also black nylon garand type slings in use through the 80s.