Well, it's not SW. Pratt & Lambert has Stainsheild that could be an option (Sherwin Williams owns Pratt altho they are not sold in the same retail locations). I'm not crazy about deck stuff from SW. JMPO. Colorwise, go to Lowe's and buy a $5 or $6 tester can of Cabot's Dune Grey. Can also order Cabot's testers of stain colors directly from their website. I've custom mixed stain colors using those tester cans. Has to be a 50/50 ratio, however.

What're your summers like, Nancita? What exposure does the porch have and what do you use it for? For our front, north-facing walk-in porch I chose a traditional Charleston green, a regional color which is almost black, for a deep, cool look that would harmonize with the lighter green foliage all around, but we were forced to go light on the porch we sit out on because the summer sun on even a medium green here will make it too hot to walk on. I noticed on browsing the web that current front porch floor colors are typically deplorably limited and boring, but I would think any color that was considered generally acceptable for a front door could be used in a somewhat muted or darkened, or perhaps lightened, version without raising eyebrows. For back deck color, you're outside but still separated from "nature" while sitting on it. Would you like a look that reinforces the shelter feeling (interior-style elements and colors carried outside), or would you like to embrace nature more and feel more as if you were sitting in a park or woods, only without your chairs sinking in? :)

Pics of the house would help you get help.

Love that SW raisin! The cedar on the siding stain and deck would look great as long as it is opaque enough to cover what it already in existence. The paint experts at your local SW store could recommend the right products. Good job!