Idioms with colours

to be browned off: to be bored, annoyed at something
I’m browned off with this place. There is nothing to do here.

to be colourless: to lack personality, to be boring.
Nothing he said stands out in my memory. I’m afraid he’s a dull, colourless man. 
to be off colour: to be not quite at one’s best, to feel queasy or slightly ill.
She’s a little off colour today because she was up very late last night and had too much to drink!.

to give/lend colour to: to make (an account, story, explanation, etc.) more credible or more believable.
 The broken window on the ground floor lent colour to her story that her house had been burgled

a highly coloured report: a report that is exaggerated or biased.
I read the government’s highly coloured report on the great state of the health services.

to see someone in his true colours: to understand someone’s true character, often for the first time.
As soon as he made a fuss about returning her money, I saw him in his true colours.

to show oneself in one’s true colours: to reveal one’s true nature.
When he lost his temper at the party, he showed himself in his true colours

with flying colours: with great success, with distinction.
We were all expecting him to fail, but he passed with flying colours.

to paint in bright/dark colours: to describe something in a flattering or unflattering way.
My brother pretended he was doing well financially and painted his life there in the brightest colours.

a golden opportunity: a great opportunity that might never come again
This is a golden opportunity to make a business deal with that big company.

a golden handshake: a large sum of money paid to a retiring manager or director, or to a redundant worker.
The company chairman received a huge golden handshake on retiring.

a golden boy: a young man idolized for a great skill, usually in sport.
David Beckham is the golden boy of English soccer

the silver screen: the cinema
Valentino was one of the earliest stars of the silver screen.

get gray hair: to have one's hair turn gray from stress
Our teacher is getting gray hair from stress.

a gray area: something that is not clearly defined and does not conform to an existing set of rules, neither black or white, neither one way or another way
The issue of the tax on children's toys is a gray area for the accountant.

gray matter: brains, intelligence
I wish that my friend would use his gray matter more effectively when he is making his crazy plans.
** Gray (USA) Grey (UK)