If you’ve ever heard someone say they were feeling blue or that a colleague got the green light, you’ve already met colour idioms — those little splashes of colour that English speakers slip into everyday conversation. They make speech vivid, natural and sometimes a bit theatrical, which is exactly why learners at B2 and C1 level should get comfortable with them. Use them well and you’ll sound far more native; misread them and you’ll end up wondering why anyone is painting a town or talking about moons. In this lesson we’ll walk through the most common colour idioms in British English, group them by colour, and finish with a quick quiz so you can test yourself.
Red idioms
Red is the colour of strong emotion in English, so it’s no surprise that many red idioms involve anger, danger or excitement. When someone sees red, they suddenly become furious — think of a bull charging at a matador’s cape. If a business is in the red, it’s losing money or overdrawn at the bank; the opposite, naturally, is being in the black. Red tape refers to excessive bureaucracy and pointless paperwork: “We’d love to open a new branch, but the red tape is endless.”
A red herring is a misleading clue or a distraction — a favourite device in detective novels. If the police catch someone red-handed, they catch them in the very act of doing something wrong, usually a crime. And if you fancy a wild night out, you might paint the town red, meaning you’re going to celebrate noisily and probably stay out far too late.
Blue idioms
Blue tends to carry a sense of sadness, surprise or loyalty. Feeling blue simply means feeling sad or low — “I’ve been feeling a bit blue since my best friend moved abroad.” When something happens out of the blue, it happens completely unexpectedly, like a clear sky suddenly producing a thunderclap. Something that occurs once in a blue moon is extremely rare; a real blue moon (the second full moon in a calendar month) only happens every few years.
If a friend is true blue, they are loyal and trustworthy through and through. Blue-collar describes manual or industrial work, while a person of blue blood comes from an aristocratic or royal family. Notice how the same colour can stretch from sadness to nobility — context is everything.
Green idioms
Green in English idioms often signals envy, permission, nature or feeling unwell. When someone is green with envy, they are intensely jealous — perhaps of a friend’s new car or holiday plans. The green light means permission or approval, and to give someone the green light is to let them go ahead with a plan: “My manager finally gave me the green light to launch the campaign.”
If your neighbour has a green thumb (or in British English, often green fingers), they’re naturally talented at gardening. Feeling green around the gills, on the other hand, means looking ill or seasick — a charming way of describing a queasy face. Finally, the proverb the grass is always greener on the other side reminds us that other people’s lives often look better than our own, even when they aren’t.
Black and white idioms
Black and white idioms tend to deal with clarity, contrast and morality. If something is in black and white, it’s written down clearly and officially. The black sheep of the family is the member who is different, often disapproved of. The black market is the illegal economy where goods are traded outside official rules. To black out is to lose consciousness or, in another sense, for a city to lose all its lights. If you’re in someone’s black books, they are annoyed with you, and a black-tie event is a very formal occasion requiring a dinner jacket.
White idioms often soften or excuse. A white lie is a small, harmless untruth told to spare someone’s feelings — “Yes, the haircut looks lovely.” A white elephant is an expensive possession that turns out to be useless: think of a giant exercise bike now used as a clothes rack. White-collar describes office or professional work, the counterpart to blue-collar. To raise a white flag is to surrender or admit defeat, and to whitewash something is to cover up unpleasant facts and pretend everything is fine.
Other colour idioms
Plenty of other colours pull their weight in English. A yellow-bellied person is cowardly — a phrase straight out of old western films. Being tickled pink means being absolutely delighted, while being in the pink means being in excellent health. A grey area is a topic where the rules aren’t clear-cut, neither right nor wrong. A golden opportunity is a chance too good to miss, and every cloud, as the saying goes, has a silver lining — a hopeful detail inside a difficult situation. Finally, if you’re in the dark about something, you simply don’t know what’s going on.
Common mistakes
The biggest trap with idioms is translating them literally from your own language — or worse, translating English idioms word-for-word into another. “See red” has nothing to do with looking at the colour red; it means becoming furious. “Feeling blue” doesn’t mean you’re cold. “Once in a blue moon” isn’t an astronomy lesson. Treat each idiom as a fixed expression with its own meaning, and learn it as a chunk rather than as separate words. It also helps to notice which preposition or verb is fixed: we say in the red, out of the blue, in the dark — change the preposition and you change the meaning, or lose it altogether.
Mini quiz: match the idiom to its meaning
Try matching each idiom (1–10) with the correct meaning (a–j). Answers are below — no peeking!
- To see red
- Out of the blue
- Green with envy
- A white lie
- A grey area
- A silver lining
- In the red
- Once in a blue moon
- Tickled pink
- A red herring
a) Very rarely
b) A misleading clue
c) To become very angry
d) Extremely pleased
e) Owing money or overdrawn
f) Unexpectedly
g) An unclear or ambiguous situation
h) Intensely jealous
i) A small, harmless untruth
j) A positive aspect of a bad situation
Answers: 1-c, 2-f, 3-h, 4-i, 5-g, 6-j, 7-e, 8-a, 9-d, 10-b.
How did you do? If you matched seven or more correctly, you’re well on your way to using colour idioms naturally. The best way to lock them in is to hear them in real conversation, with real teachers, in a country where English is part of daily life. If you’d like to practise your English in Malta with small classes and friendly teachers, request a quotation here and our team will be in touch.
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