I'm a little leery of custom mixing a color in case I'm short by a quart or 2, but in looking at the swatches, the grey does seem on the dark side.
I like the cream color and it was under consideration, but I thought the grey might be easier to keep clean - actually, that it would not show the dirt so much.
Although monitors can differ, how does the cream swatch seem to compare to the paint on your deck?
http://www.pachena.com/KiwiGrip_Colors.asp