We live in Manitoba, in a house with white stucco, grey shingles and black shutters. I would love to paint the stucco grey. Is this a good idea?
Considering how brutal Manitoba's winters can be, I can only imagine how dirty your white stucco house becomes. Painting stucco is ideal, as it can be very difficult to clean.
And if you apply the appropriate product, you should be good to go. If you want to enhance the look with an Old World pebbled finish, you need to replaster first, then apply the pebbled mixture.
Shades of grey are always hard to choose. I would let the roof be in the medium range, the walls light and the shutters the darkest. Stick with true grey and avoid green-grey. I find that a blue-grey can be very pleasing with the hue of the sky. Another option is taupe (but avoid any pinkish tint). Consider your colours when the sun is at varying heights:
Some shades of grey (in wall colours as in books) can't stand the light of day.