Idioms and phrases using red
A “red-letter day” is one of special importance and good fortune. To “paint the town red” is to celebrate. To “see red” is to be angry. A “red herring” is a distraction, something that takes attention away from the real issue. If a business is “in the red,” it is losing money.
Idioms using green
“To go green” is to become jealous. A “greenback” is slang for a U.S. dollar bill. If you have a “green thumb” you are a good gardener.
Idioms using blue
If you are “true blue,” you are loyal and faithful. “Feeling blue” is feeling sad. Something “out of the blue” is from an unknown source at an unexpected time.
Idioms using purple
“Purple speech” is profane talk. “Purple prose” is writing that is full of exaggerated literary effects and ornamentation.
Idioms using yellow
If someone is said to have a “yellow streak,” that person is considered a coward. “Yellow journalism” refers to irresponsible and alarmist reporting.
Idioms using white
A “white elephant” is a possession that costs more than it is worth to keep or an item that the owner doesn’t want but can’t get rid of.
Idioms using black
A “black hearted” person is evil. If a business is “in the black,” it is making money. A “blacklist” is a list of persons or organizations to be boycotted or punished.