show one's colors

[show one's colors] {v. phr.} 1. To show what you are really like.

We thought Toby was timid, but he showed his colors when he rescuedthe ponies from the burning barn.

2. To make known what you think orplan to do.

Mr. Ryder is afraid that he will lose the election ifhe shows his colors on civil rights.

We would not help Jim untilhe showed his colors.