blue Idioms 

black and blue

- bruised

My shoulder was black and blue after I fell down the stairs.

blue blood

- the blood of a noble/aristocratic family

Many of the blue bloods of the town went to the opening of the opera.

blue in the face

- to be very angry or upset, to be excited and very emotional

I argued with my supervisor until I was blue in the face.

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/have the blues

- to become sad or depressed

The dull cloudy weather has caused me to get the blues.

out of the blue

- without any warning, by surprise (like coming out of a blue sky)

Out of the blue my friend decided to quit his job and go to Europe.

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.

talk until one is blue in the face

- to talk until one is exhausted

I talked until I was blue in the face but I could not change my teacher's mind about my essay.