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
'violet (the flower)'
so maybe, it is form ion and not iolè...