失色的英文：
lose countenance; pale

参考例句：

As the name of the Indian Diamond passed her lips, I saw a change come over my admirable friend
她嘴里刚吐出那颗印度钻石的名字，我就看见这位可敬的朋友顿时失色。

lose是什么意思：
v. 遗失；输掉；浪费；被...夺去；不明白；逃避；错过

to lose; to miss; to disappear; to mislay
遗失

A tale never loses in the telling.
故事总是被人们说得添枝加叶的。

Merry is he that has nought to lose
人无所失,不亦乐乎

countenance是什么意思：
v. 赞同；支持
n. 面容；赞同；鼓励

so grave and unfired a countenance
十分严肃冷静的面容

The candle illuminated her countenance.
那支烛正照着她的面孔。

They would never countenance lying.
他们对说谎的行为决不姑息。

pale是什么意思：
adj. 苍白的；无力的；暗淡的
v. （使）苍白，失色
n. 栅栏；范围

The flowers in their hair are pale and faded.
她们发上的花朵已经褪色枯萎了。

The water was of a pale, neutral color.
这水是一片淡灰色。

She paled with shock at the news.
她听到那消息大惊失色。