Jerry:
Coke is usually a light grey, silvery color, at least from the old
beehive or the more modern non-recovery systems (you didn't specify era). I
am less sure about coke from a byproduct plant.

Eric Hiser
Phoenix, AZ

I wouldn't say silvery... it's not shiney at all, and nowhere near that light in color. I remember handling it for my neighbor's forge when I was a kid. If I had to match it for color, I'd say somewhere between Floquil Grimy Black and a photographer's 18% gray card (anyone still use those things?)

If I had to build a load, I'd use scale coal or ballast and spray paint it with a dead flat dark gray., maybe a dark gray automotive primer from a spray bomb.