Hazel was an eye colour. Hazel eyes were typically a mix of green and brown, but could also be a mix of gold and brown. They were sometimes referred to as "hazel-green". (PROSE: The Reproductive Cycle, Who Killed Kennedy)
The Doctor had hazel-coloured eyes during the war, (TV: The Day of the Doctor) tenth, (TV: The Parting of the Ways) eleventh, (TV: The End of Time), thirteenth, (TV: Twice Upon a Time) and fourteenth incarnations. (TV: The Power of the Doctor)
Companions of the Doctor with hazel eyes were Barbara Wright, (TV: An Unearthly Child), Jo Grant (TV: Terror of the Autons) Romana in her first incarnation, (TV: The Ribos Operation) Nyssa, (TV: The Keeper of Traken) Bernice Summerfield, (PROSE: Prelude Love and War) Mary Shelley, (AUDIO: The Silver Turk) and Amy Pond. (TV: The Eleventh Hour)