Depending on what kind of finish was put on you might have to use md80 stripper followed with an oxalic acid wash. www.woodrich-brand sells both and a not bad question area.

I hear you. We just had a fence put in, and I want to stain it. A medium dark brown, without too much red, but not gray looking... I've got 5 quarts and three sample size stains, and so far nothing is exactly right.

I wouldn't use any of those deck paints again. I had the Behr stuff and had to redo it every year! 5 year guarantee,,,,sheesh. yeah right! Penofin has a great oil/stain for exterior wood.The Verde and the Red Label have 99% UV protectants. the red label is Ultra performance against mildew, rain/snow/high altitudes. they have red label, blue label, verde and marine finishes. A lot of colors too. http://www.penofin.com/wood-stains/verde-environmental-wood-stain

you're picking the cooler gray tones. That's why you're seeing blues and purples. you need to choose warmer grays. BM Smoke embers is a nice gray I also stuck in some reddish beet and raisin colors. I think the Raisin color would look nice next to the brick. Any of these would also look very nice w/your bricks. I love the midnight oil for a trim color And yes, if you paint the deck, it will need to be done yearly. I don't care if it says 5 years, it never is. I painted mine every single year. I finally said forget it, and went to composite decking. make sure the deck stain (it can be an opaque stain) or deck paint has UV qualities to it. it will help make it last.