The wife makes fashion calls in our house. My wife's opinion on how kilts are worn are as such (in general):

Fancy - the whole kit
Dress - hasn't come up yet
Business casual - polo with nice shoes like what Sport kilt calls cali brogues
Casual - T and combat boots

She considers the any none plaid kilt but the khaki to be casual. The khaki can be a business if worn with a nice shirt. Kind of like khaki jean over blue jeans.

Jim