I've heard a lot of different variations of the spellings of their names:

Asukuuru and Kufiiyu, Ascule and Que Feuilles, etc. I imagine that the second spellings are the correct ones, since Lumiere and Eclair are both French as well, but two-word names don't look right to me, so for now I'll go for a mixed version.

The silver-haired younger looking one is Ascule, and the purple haired one is Kufiiyu/Que Feuilles.