If I recall correctly, the scanlations said something in the lines of natural or neutral. Spanish tranlation says "ivory", but that's kind of on the lines of white-like and beige after all.

I've seen two websites so far saying green.

This is getting confusing. Might as well stick to white-like colors so it complements Eriol's black. Or something. Dunno.

Afterthought: maybe she was thinking of hair color? That she doesn't like bottle blond or those outrageous red tones L'Oreal style? it's not like it matters to her a lot since she only dates dark-haired guys