Some stack rock pics..

Your house is beautiful as is. I cant imagine improving it with those rocks in that photo.

Rock would be a mistake. You need to paint/stain the garage door and column faced in wood with a color that coordinates with the existing colors, predominantly grey. I am not talking about a solid grey, but one of the muted greys stains that brings out the grain of the wood. What bothers you is that the brown of the wood is too distinct and overbearing. You need a muted grey-stained-wood look to go with the brick and mortar. The brick and mortar are variegated shades of grey. You need to tone down the color of the wood, but do not replace it. The brick (with the distinct grout lines) and stone, with more grout, would make the facade of the house too busy. You need to simplify the existing pattern and tone down that brown that does not go with the grey brick and mortar. You may be able to keep the brown trim on the door and windows.

I love the contrast of the current brick with your column and garage. I wouldn't change a thing!

I like the wood and the contrast as well. If I were to change anything it would be the horizontal band of stucco. I don't think that fits in with the house at all. Possibly make it the same stone as the seat wall or just darken the color of it to match the existing tones here. I wouldn't add any new colors. Looks like a lovely home.