You didn't address the issue of underwear and skin in contact with said hakama. Streams of indigo-blue water used to go down the drain when I'd shower after class.
And that, folks, is the origin of the Blue Men of Mali/Sahara (and the inspiration for the desert dwellers of Frank Herbert's "Dune").
Carol's vinegar suggestion reminds me of an old dye-fixing formula that works on most colors: the amount of vinegar she mentioned, plus the addition of a half teaspoon of cream of tartar and a pinch of salt. I used to use that when I did tie-dying back in the 19(mumbles...mumbles)s.
Whoa! To clarify, my vinegar comment was not per fixing indigo dye -- it was per fixing polyester pleats. As far as I can tell (and judging from many anguished smurf postings) the vinegar soak to somehow "fix" indigo just doesn't work. It might have been a treatment for the fabric itself, much like back in the 19(mumble. . . mumble) before the days of newfangled pH-balanced shampoos, we used to final rinse hair with a weak solution of vinegar (for brunettes) or .lemon juice (for blondes) to neutralize the alkalinity of the soap (Prell! Yowza!). In none of these cases did the acid have anything to do with the color.