Red tape
Excessive bureaucracy or rules that delay action.

In the pink
In very good health.

Seeing red
To become very angry.

Caught red-handed
To be caught in the act of doing something wrong.

Green with envy
Very jealous.

Out of the blue
Unexpectedly; without warning.

Once in a blue moon
Very rarely.

Feeling blue
Feeling sad or depressed.

White lie
A harmless or trivial lie.

Black sheep
A person who is different or undesirable in a group.

Golden opportunity
A perfect chance to do something.

Red herring
A misleading clue or distraction.

Caught in the crossfire
Being caught in a conflict between two parties.

Black and white
Clear-cut; no gray area.

Green light
Permission to proceed.

Tickled pink
Very pleased or delighted.

Red flag
A warning sign.

Brown-nosing
Flattering someone to gain favor.

Blue blood
Of noble or aristocratic descent.

Yellow-bellied
Cowardly or timid.