Thanks for the ideas. I just ordered some from W. Brewin. They had bottle green in the right size (I hope), though I had to browse to find them.

Ordered a pair for myself too, just to see. They now have lycra (maybe they always have) in their adult kilt hose and at $7.50 I figured I would see if they are any more comfortable than the Gaelic Themes ones I currently have.

So for anyone else looking, W. Brewin has several colors (at least: red, navy, grey, and bottle green) in three different youth sizes.