She is in a white mourning dress.

她身穿素服。

《新英汉大辞典》

White had never been taken as the color of official robes because of the practice of being the color of mourning dress.

白宫从来没有带颜色的长袍，因为官方的习惯做法，采取洁白颜色的丧服。

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And some people have taken to criticizing others who don't strictly conform to the mourning dress code, which allows black or black with white.

哀悼期的着装规范只允许黑色或者黑色和白色，有人已经开始批评没有严格遵守规范的人。

youdao

Nahla's mother Samirah(ph) and her sister Iman still dress in black in mourning for her.

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Mosi cloth is used to produce a variety of clothing from dress suits and military uniforms to mourning garments.

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Today I will dress in white, the color of mourning, to attend the funerals of the six Sikhs who were killed and offer support for their families.

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