[误] He showed his true face as soon as he got the power in his hand.

[正] He showed his true colors as soon as he got the power in his hand.

注：注意，这里的 colors 要用复数，而且这一短语带有很强的贬义。再看下面的句子：She finished the work

in flying colors(她出色地完成了任务)。这里的 colors 指“彩旗”，而飘扬的彩旗可是胜利的标志噢!