Blue is more than just a colour.

You can:

• sing it - The 'blues': Muddy Waters
• wear it - A blue hat
• feel it - depressed, down in the dumps
• see it - the bird came out of the blue and flew into my windscreen
• do it - dye, tint or paint
• watch it - x rated movie
• eat it -  cheese: Stilton
• say it -  cursing, swearing: the air is blue

Blue grammar:

Blue can be a noun, adjective or verb:

Noun: a color whose hue is that of the clear sky or that of the portion of the color spectrum lying between green and violet

1. Blue is his favorite color.
2. Shades of blue

1. I talked to him until I was blue in the face, but he wouldn't listen to me.
2. He is feeling blue

1. They blued the shirts of their uniforms.
2. They dyed their hair blue (blued)