Red, Blue, Yellowas red as a rubydeep red
The office assistant was wearing lipstick that was as red as a ruby.
catch (someone) red-handed- to catch someone in the middle of doing something wrong
The woman was caught red-handed when she tried to steal some cosmetics.
paint the town redto go out and party and have a good time
When my cousin came to visit us we decided to go out and paint the town red.
red herringan unimportant matter that draws attention away from the main subject
Talking about the other issue was a red herring that did not do anything to deal with today's problem.
roll out the red carpet- to greet a person with great respect, to give a big welcome to someone
The government rolled out the red carpet when the politician came to visit.
see red- to become very angry
My boss saw red when I told him that I would not be coming to work today.
blue blood- the blood of a noble or wealthy or aristocratic family
Many of the blue bloods of the town went to the opening of the opera.
blue-ribbon- of superior quality or distinction, the best of a group
A blue-ribbon panel of experts were asked to suggest a new policy for the city.
get the blues- to become sad or depressed
The dull cloudy weather has caused me to get the blues.
out of the blue- without warning, happening suddenly and unexpectedly
The decision to close the store came out of the blue.
talk a blue streak- to talk very much and very rapidly
The woman beside me on the bus talked a blue streak for most of the journey.
yellow-bellied extremely timid, cowardly
The man is yellow-bellied and is never willing to fight for what is right.
yellow brick roadA path believed to lead to success or adventure.
Jenna took the internship thinking that it would be the yellow brick road to her dream job.
yellow dogA despicable person or thing.
I can't believe you get so invested in these debates—all politicians are yellow dogs that can't be trusted.
yellow lightAn indication to slow down, likened to a yellow traffic light, which means slow down, proceed with caution, or prepare to stop.
I would not ask her out yet, dude—she was totally giving you the yellow light.
yellow pressJournalism with the primary aim of sparking reader interest—reporting the facts are secondary.
I can't believe you read those tabloids—they're just yellow press stuffed with ads.