I saw a dark brown fertile field in which a plough was cutting large furrows.

我看到一块深褐色的肥沃田地，那里耕犁正犁出宽大的犁沟。

《柯林斯英汉双解大词典》

A dark brown little notebook bag?

深棕色的电脑包是吗？

youdao

Mrs Merrick wore a dark brown dress.

梅立可太太穿一件深褐色的衣服。

youdao

But yeah, 'cause my hair is a really dark brown,

但是，因为我的头发其实是很深的棕色，

忘不了的生日礼物 - SpeakingMax英语口语达人

The filling caramelizes and turns a dark brown.

NPR: Baking by Senses and Memories

He described the dogs as two retrievers, one a dark golden brown colour and one white, and a small Jack Russell.

BBC: Alicia Williams and David Platt: Wrexham river victims

Mr Speight, who is 6ft, was wearing a brown suit jacket with dark jeans and a brown flat cap.

BBC: Family plea to missing presenter