As the title says...
Hard to say for me...
red hair / blue eyes
red hair / purple eyes
black hair / red eyes
black hair / purple eyes
brown hair / blue eyes
brown hair / green eyes
brown hair / yellow eyes
blonde hair / blue eyes
blonde hair / green eyes
blonde hair / red eyes
blue hair / red eyes
blue hair / blue eyes
purple hair / red eyes
purple hair / blue eyes
...and others have all been attractive to me, lol.
One should include in their reply at least one character example and which combination they have.