短语 with flying colours 的意思是某人表现出色，取得了极好成绩。

例句

My daughter passed her exams with flying colours! We're going out to celebrate tonight.

'Did John pass his driving test this morning?' 'Yes, he passed with flying colours.'

请注意

还 有一个短语to show one's true colours, 意思是当某人的本来面目或性格表现出来了。有一支很有名的歌 True Colors, 歌词中有一段 "And I see your true colors shining through". 意思是 I can see your real personality and who you are 我能看到真正的你。但这个短语也可以带有贬义，比如:

Tom showed his true colours in the restaurant – he was so impatient and started shouting at the waitress!

Tom 在餐厅里终于原形比露了，他很没耐心，对服务员大吼大叫！

请注意单词'颜色' 在美语里的拼写是 color, 在英式英语里是 colour.