Is a Kilt like Khakis? Color Question

[YoungMan]

I currently own a black stewart kilt, black sporran, black hose, red flashes, black shoes and so forth. So from the waist down things are pretty dark. My question is: "Can you wear whatever you want upstairs like with a pair of khakis?"

My friend suggested I get a black vest to go with everything, but I kind of want to avoid the Johnny Cash route. I have a tan herringbone vest onhand and I really like the way it looks with a white or blue shirt. I have a picture from the waist down which gives a pretty idea of the contrast.
Edit: Thanks to McFarkus for the Photobucket suggestion.
I just wanted to get some thoughts on the idea as I imagined a family tartan wearing person wouldn't limit themselves from the waist up on the basis of the clan tartan.

Side question: If the weather's a little warmer but you still want a little dressier look, would a vest over oxford be fine for a night out?