An interesting example is the sea people portrayed in Toni Diterlizzi's and Holly Black's
Arthur Spiderwick's Field Guide to the Fantastical World Around YouHere is a link with an example. http://mizdracona.deviantart.com/art/Spiderwick-Mermaid-68793005
The way sea animal body parts are incorporated gives it a realistic, sea-like feel. The 'eyebrows' are simple color patterns that mimic mammalian eyebrows. Also see the way hair is represented with fins and tentacles. I think this approach might work with Klyros females.
Below is a mohawk, which is a hairstyle that originated from a Native American tribe and hairstyle.
I feel that the male Klyros head fin is somewhat similar to this with webbed skin in between. I do think it might be nice to have fin color variation as a hair color choice eventually. A splash of red or yellow might help make the fin more attractive.
On a totally different subject, in response to the note that Klyros are skilled in decorative magic, I feel that they should be able to
1. create pictures which move
2. create "windows" such as are found in the Hydlaa secret garden, these would make the Klyros feel closer to nature while in buildings
3. have pictures and paints which change color, much as some squid can do with their skin
4. use magic to "bind" elements such as water and air and turn them into sculpture
