I went ahead with the smoke color that I originally asked about. It is a very light gray.
Toofast,
Sorry no pics! But I agree that you should go as light as possible as the deck can get hot when temps are upper 90s/ 100s which we get here in OK. In hindsight having something with a little tan in it and not so gray might have been better color match with our tile and coping but we are very happy with the deck. Looking at your colors, it seems that Pebble is the lightest and appears fairly neutral. Outback is more gray, sandstone and dune more green, and canyon seems to dark too me if you are worried about heat. Again it depends on what else you are matching it with but the Pebble looks like it would match with a wide variety of colors.
You can get a cast on hardner/color treatment over the base to alter the color somewhat. It was very expensive for this to be done so we did not opt for it.
Isaac-1
We are very happy with ours. The Butterfield color is in bags that they toss in the mixer and let it mix for 15 minutes or something. The color is not perfectly even but I don't know how much the rock salt treatment might have affected that. The variation in color is subtle. Hard to goof up unless they cut short the mixing time.
Just an overall word on decks: a friend had a pool put in about the same time as ours. His deck is stamped, stained and sealed. It is very slick when wet, even though they put some sort of additive for traction into the sealer. Every time we are over there, someone slips and falls. I was worried the cast on hardner would also make a slick finish when wet, but I do not know for certain. Our unsealed rock salt finish has excellent wet traction and so far has not shown any inclination to stain even though it is a light color.