Hazel as a colour name comes from the hazel tree (Corylus avellana) — one of the earliest trees to colonise northern Europe after the last Ice Age. The hazel was fundamental to early human culture — its flexible branches were used for wattle construction, its nuts for food. As an eye colour description, "hazel" entered common usage in the 19th century to describe eyes that combine brown, green, and gold.

Warm, complex, and autumnal. Hazel is brown with a hint of green — it has the earthiness of brown with a subtle natural liveliness. As an eye colour, it carries associations of depth and complexity — hazel eyes are famous for appearing to change colour in different lighting, which gives them an association with mystery and emotional depth.

The hazel tree has deep roots in Celtic mythology — it was considered the tree of wisdom, and hazelnuts were associated with knowledge and inspiration. The Salmon of Knowledge in Irish mythology gained its wisdom by eating hazelnuts fallen from hazel trees. In British folklore, hazel branches were used for water divining rods. The colour hazel sits in the rich tradition of names derived from the natural world — a small part of the vast vocabulary humans have developed by observing their environment.