I'm sure I've seen a photo somewhere which shows both dark grey and black G60 LTD's. Here you go:

No idea how many were built in each colour though.
Oh, and I'm looking at an article from Autocar & Motor dated Oct 11 1989 which says the wheels are 6.5" wide with 195/50R15 Pirelli P600's. And in 1989 the price of one of these things was £22,570. (I bought my GTI in '89 and that cost me about £14K fully loaded, for reference).
EDIT: the arch trims were standard small-bumper width. Cars built in 1989 were LB7V graphite grey and in 1990 LP9V metallic black - I think.