A lot of places can supply these hose, sometimes called "popcorn top hose" sometimes called "pipers hose." They can be had in colors other than plain white. I have two pair, one in bottle green and one in lovat green.

The Museum gift shop used to carry them but we don't any longer. If anyone is interested we still have ONE pair left in lovat green for $35. I can't recall the size right now but I can check in the shop when I get in this morning.

I beleive USA Kilts can also supply them. I'm pretty sure Scotland Yard can. Other places, as well, no doubt.

I've also seen some people wear popcorn hose tops -- just the top that they slip on over their regular hose of the same color. And I've seen some gents wearing hand-knit hose that were made with a very similar top.
~M