It takes more time to set up the knitting machine to make diced hose, and if they're done by hand, each colour change needs to be knotted and changed...more time, more money.

I agree with previous posts: I wear cream/off-white hose for semi-formal/day use, and my dark green/navy for formal/evening occasions. Even my former pipe bands didn't wear white hose. I only wore off-white hose, when I danced. (No matter how I word that, it sounds like I danced naked wearing only my hose. ) I wear my black hose with a kilt that is predominantly black, such as my Black Stewart SK. Another thing to consider, is to minimize contrast of your hose with your shoes if not wearing Ghillie Brogues i.e. black shoes with black hose. I will be looking for Lovat blue hose for my MacTavish kilt I'm buying from SWK, but off-white will be just fine. For formal occasions with the MacTavish tartan, I'd wear my navy hose.