Since yours is 1993 and has grey covers, and mine is Aug 1993 and has grey, I checked Fallon's Belt-Drive guide and the Haynes manual.
All the IMAGES of the first runs had the dark grey covers - not black tho' Fallon incorrectly states they were were black.
Even the VisorDown retro review shows a 1993 with grey:
http://www.visordown.com/road-tests-...900/14265.html