as pale as a ghost 面无人色；面色苍白

【例句】
At first, I was as pale as a ghost because I was so nervous, but later I was able to find my feet.
开始的时候因为紧张，我会面色苍白。但是之后我就适应了。

The fact that she grew pale showed her speechless fright.
她面无人色说明了她说不出来的恐惧。