what I found: ioeis: descibing a deep shade of blue (I can't translate it properly, because my Greek dictionary is Greek-Dutch, and I have trouble translating what it says into English), so that describes a colour. also: io-eidès: violet/dark-coloured.
and: io-blepharos is translated as: with violet coloured eyes (so the io part definately descibes the violet colour)
what my name book says on this name:
from Greek
ion 'violet (the flower)' and
anthos 'flower' or it's derived directly from Latin
violante from
viola 'violet (the flower)'
so maybe, it is form ion and not iolè...