The color of the garage goes with the olive on the top of the house. The faded green on the bottom does not. I'd recommend painting the bottom of the house to match the top. You can stone accents on the foundation. I wouldn't add more stone. If you could get a match, possibly stone matching the foundation on the side of the garage.

Your house is, no offense, a visual mish-mash right now. You have three siding types(board and batten and two different lap siding styles), three colors + white trim and then the stone. The last thing you need is yet another type of stone accent. You need to consolidate, not add more textures/colors/products.

How far are you willing to go/spend? I’m assuming the garage was an add-on?

The ”ideal” solution would be to get rid of the vinyl siding(it is a garbage product) and put matching hardie-board siding on the garage, then paint ALL of your siding a single color. Your cheapo vinyl siding will always look bad next to a superior product like Hardieboard right there staring it in the face.