I have a similar pair of pants and I tend to balance them with a pair of longwings or boots since they are not truly dressy and benefit from the chunkiness of the broguing. I'd say to go with whatever color you typically match to the given shade of charcoal (I try to steeze out with dark brown if I am wearing them during daylight hours and stick to black at night).
From what I steal from tumblr and such, Cucinelli tends to pair khaki cargos with heavier shoes and layering on the top, such as quilted pieces or heavier fabrics. The ideal I associate this with is a hunting outfit of some sort, so that tends to mean patch pockets, elbow patches, corduroy, scarves and down vests.
Overall I would try to not consider these dress pants. Wool flannel is great for colder weather and you will be able to dress these up for a casual night out without seeming too stuffy and slick.