show one's colours BrE
show one's colors AmE

You don't want to be around when he shows his true colors.

"Is this what war does to people, or do they just show their true colors?"

But the past few weeks he had shown his true colors.

Their screens are small, and some do not show color, in part to save power.

"You can't expect such a child to show his or her true colors for the first 30 days," he said.

Still, there are times when they feel forced to show their colors.

But it was under game conditions where the Voodoo5 5500 showed its true colors.

He nodded, his face showing color again, and walked to the door.

The light was clear and white, brilliant enough to show true colors.

He could hang it all out, show his true colors.