The same goes with skin colour. I can understand needing a Fantasia to change the shapes of your character's features, their gender and their race, but all colour related changes should be editable via the aesthetician.

In many instances, eye colour is being matched with the player's current hair colour as a way to make the eyes "pop" by using contrasting/brighter/darker colours to the hair. This is all made irrelevant when a player decides to change their hair colour, where the eyes will no longer match and requires them to buy another Fantasia for such a minute detail.

This goes for both skin and eye colour, as many times a player will look at all of the different lighting options given when editing their character, then will find out later that a certain zone makes their skin or eyes look a way they don't like.

I read a great suggestion earlier from someone where they posed the idea that there should be a timer mechanic after using a Fantasia:
Once the character finished re-editing their character, there should be a 1-3 hour window where they are allowed to go back and re-edit up to 2 more times. This would give the player time to visit their favorite zones, wait through a few day/night cycles, do some G-pose, try on some new clothes, etc., to get a feel for how their new character looks in different circumstances.