If you are using a prefinished cement board color, I'd start there and get samples. As far as the stucco goes, if you are using an acrylic stucco, the supplier can make a sample board of several different colors for you to try. The texture of the stucco will make a big difference in how the color looks and reflects light. Don't try to pick a color off of a paint swatch and look at it in all light directions. The area in which you live can be a big factor. In areas that have harsh winters some colors look out of place, but do not in the spring and summer. You have a fairly neutral base to start with, a greyish color with slight green/brown undertones will look interesting and blend will with nature and natural elements like the stone. Look at SW Anonymous or SW Adaptive Shade as a place to start. If you are using paintable cement board, make a sample too. Any color will look different depending on the texture.

Is this an existing home? Do you have photos of the exterior or elevation drawing ?

It is new construction. Ranch home with shed dormers to make it not look like a ranch