I like the dark gray. Its great if you have rocks that look the same as thr landscape boulders, more natural looking.

Would you consider a plant ground cover instead of stone?

Not sure how complementary it will be. Given its prominence and for more curb appeal, I’d expand the area and create a softer, layered natural focal point.

Get some phlox subulata, Moss Phlox. Buy a bunch of plugs, it spreads nicely and will look a hell of a lot better than a rock surrounded by stones.

i would not do a rock border It will require trimming and always looks too busy. just cutva trench.