Not sure there was a lot of 'quality control' on the colour of Bally legs.  Seemed to range from almost black to dark grey, non hammertoned.  Stern were silver grey with hammertone.

+1

With regard to legs after the 31 inch chrome.

Bally EM legs were powdercoated charcoal black - Early to mid 70's
Bally EM Legs were powdercoated Gun Metal Gray - Late 70's - Mid 80's.

The "Gun Metal Gray" is really close to a very dark gray to a light black. Different manufacturers used different paints and the color variations were slightly different. I have flyers of all the SS machines, and the color differences are significant. There was a possibility that Space Invaders was a charcoal black as suggested on the flyer.

At some stage in the 70's Bally shipped light gray legs for a period of time. I don't know why, or for what games, but I have a couple of Bally legs that are light gray.These were painted gray rather than powdercoated.

The argument over "who is right" has been debated over the years, and every time PBR or Pinballlife release a set of legs, there are always pinball people commenting that they are wrong. There's no "correct" Gun Metal Gray, and if anyone believes there is, then they are welcome to sort out the 200 or so legs that I have in storage from Ballys from 1973 - 1984. It is almost impossible to match old legs into "sets" of four legs with the exact same color !

There is a paint I've used which is very close which I bought in a can from Supoercheap Auto. Very large cans ! I used primer, Gun Metal Gray and a clear. Cost me $70 in paints and I re painted 3 sets.

PowerPlus Etch Primer PK0060
PowerPlus Gun Metal Gray PK9190
PowerPlus Clear PK0100

This is the closest I've got to an original color - but it is lighter than the PBR Legs.