Of course, as with most historical dresses in Hollywood (or should I say unfitted historical dresses), it is not actually cut as a chiton would, but it is still a lovely dress.
I would make my version as two rectangles of blue taffeta bag lined in red taffeta, sew it up the sides and add gold buttons and loop at the shoulder. Sure, taffeta is hot, but I feel it would achieve the right look. Also, by bag lining both rectangles, I get a two colour, reversible chiton. Imagine that, a two for one! (Hmmm, maybe I should market that for the SCA...),
Add jewellery, a gold belt, some gladiator sandals and a curled updo and your ready to party with Queen Mab and the rest of Avalon!