I'd say the grey (stone) or the gold, not the anthracite metallic. Maybe the grey would be better still with a satin finish as it looks a bit too glossy.
. . . But my building was all grey , so it was like the little ornaments dissapeared in the grey if choose grey . . .
If you use the stone grey color perhaps you could apply some darker shading in the creases of the figures so that they will be more easily seen as gargoyles from a distance. Just a thought . . .