brown的基本意思是“棕色的,褐色的”,当它单独用时一般不跟不定冠词,但当它与其他的颜色连用形成另一种颜色时,一般都有不定冠词。

as brown as a berry
黝黑的,晒黑的 having skin tanned brown by the sun or the weather
A little old woman with a wrinkled face as brown as a berry told us our fortunes for ten pence.一位满脸皱纹皮肤黝黑的小个儿老妇人向我们索取十便士,替我们算命。

用作定语
▲～+n.
He wore a pair of brown shoes.他穿了一双褐色皮鞋。
It was tied up in brown paper.它用牛皮纸包着。
She fastened her brown eyes upon him.她那双棕色的眼睛盯在他身上。
Who is that man in a brown hat?戴棕色帽子的那个人是谁?
His black hat was the brown color of the earth and his clothes were dusty and torn.他的黑帽成了土褐色,衣服也又脏又破。
用作表语
▲S+be+～
Her eyes are brown.她的眼睛是褐色的。
She is very brown after her holiday in Greece.在希腊度假后她皮肤晒黑了。
He stirred the coffee until it was a light brown.直到咖啡成淡褐色,他才停止搅拌。
After the Autumn harvest, the stalks were brown and bare.秋收后,植物的茎干变得棕黄无叶。

1.brown可用作名词,作“深色,褐色”解，多不可数，表示某种形式的褐色时可数。例如:
You should fry the chicken to a golden brown.你应把鸡肉煎成金黄色。
She has stained the floorboards dark brown.她把地板漆成了深褐色。
She dressed in brown.她穿着褐色的衣服。
2.brown还可用作动词,作“(使某物)变成褐色”解。例如:
Heat the butter until it browns.把黄油加热,直到变成褐色为止。

［同义词］   bay, brick, dark, dusky, tan