24 Colour Idioms in English and What They Really Mean [2026]

Colour idioms are among the most common figurative expressions in English, and most of them have nothing to do with colour at all. Red tape is not tape, a white lie is not white, and being in the red has no colour in sight. That gap between the words and the meaning is exactly what makes them hard, and worth learning properly.

This list gives you twenty-four of them, grouped by colour, with a plain meaning and one natural example each. A note at the end covers the British spelling and the single idiom that changes between British and American English.

Blue

1. out of the blue: suddenly and unexpectedly. An old school friend called me out of the blue last night.
2. once in a blue moon: very rarely. My brother lives abroad, so we only meet once in a blue moon.
3. feeling blue: feeling sad or low. Many people start feeling blue once the evenings turn dark.
4. a bolt from the blue: a complete and sudden surprise. Losing his job was a bolt from the blue for the whole team.

Green

5. green with envy: very jealous. When she showed off her new car, the neighbours were green with envy.
6. give the green light: to approve something to go ahead. The council finally gave the green light to the new library.
7. have green fingers: to be naturally good at gardening. My grandmother has green fingers; everything she plants thrives.
8. the grass is always greener: other people's situations always look better than your own. He keeps changing jobs, always thinking the grass is greener.

Red

9. red tape: excessive official rules and paperwork. Starting the business meant months of red tape.
10. caught red-handed: caught in the act of doing something wrong. We caught the children red-handed raiding the biscuit tin.
11. in the red: in debt, spending more than you earn. Three quiet months left the shop deep in the red.
12. see red: to become suddenly very angry. He sees red whenever someone criticises his work.
13. roll out the red carpet: to welcome someone very grandly. The hotel rolled out the red carpet for the returning champions.
14. a red herring: a misleading clue that draws attention away from the truth. That whole story about the missing keys was a red herring.

Black and white

15. the black sheep: the member of a family or group seen as different or a disgrace. As the only artist, he was the black sheep of a family of lawyers.
16. black and white: very clearly one thing or the other, with no middle ground. Nothing here is black and white; a lot depends on the situation.
17. a white lie: a small, harmless untruth told to be kind. I told a white lie and said I loved the gift.
18. a white elephant: an expensive thing that is useless or more trouble than it is worth. The new stadium became a white elephant nobody could afford to run.
19. in black and white: written down officially, so it cannot be denied. Get the agreement in black and white before you start.

Other colours

20. a grey area: a situation where the rules are unclear. Whether the expense counts is a grey area.
21. show your true colours: to reveal what you are really like, usually the less pleasant side. Under pressure, he showed his true colours.
22. pass with flying colours: to succeed very clearly and impressively. She passed her driving test with flying colours.
23. tickled pink: extremely pleased. Grandad was tickled pink when the whole family turned up.
24. a golden opportunity: a perfect chance that may not come again. For a school leaver, the internship was a golden opportunity to learn the trade.

Spelling and the British-American difference

Two small points are worth flagging. First, spelling: this article uses colour, the British and Commonwealth form, where American English writes color. The idioms themselves do not change with the spelling. Second, one idiom genuinely differs: British English says someone has green fingers, while American English says a green thumb. Both mean a talent for gardening, so the version you pick quietly shows which English you use. It is also worth knowing that tickled pink now sounds slightly old-fashioned and warm, more likely from an older speaker than a teenager.

The best way to lock idioms in is to notice them in real reading and listening rather than drilling a list. Pick three from here and watch for them this week. If you like a themed set, our sport idioms guide is another. And when you want to see where your English stands overall, a free English level test gives you a clear CEFR result to build on.