Q:

Trying to recall a book - cover art heterochromia, plot with genetic mutations and a utopia

My mother remembers reading a book in the 80's, and only clearly remembers the cover art. However the date is irrelevant because she doesn't think it was new.
The cover had a face with one brown eye and one green eye.
There is a utopia verging on collapse, wherein all the people look identical. A general olive skin, dark hair, and brown eyes. There are occasionally mutants that are eradicated. The main character of the book had heterochromia and was trying to escape.
I'm sorry that all I have to go on is this, and any help would be very much appreciated

A:

Ira Levin's (Rosemary's Baby) "This Perfect Day" (1970) is a dystopian novel with the hero 

Li RM35M4419, nicknamed "Chip" (as in "chip off the old block") by his
  nonconformist grandfather Jan, is a typical child Member who, through
  a mistake in genetic programming, has one green eye. Through his
  grandfather's encouragement, he learns how to play a game of "wanting
  things," including imagining what career he might pick if he had the
  choice. Chip is told by his adviser that "picking" and "choice" are
  manifestations of selfishness, and he tries to forget his dreams.

