colour television vs television

colour television and television both are nouns.

Word	Noun	Adjective	Verb	Adverb
colour television	Yes	No	No	No
television	Yes	No	No	No

As nouns, television is a hypernym of colour television; that is, television is a word with a broader meaning than colour television:

colour television: a television that transmits images in color
television: a telecommunication system that transmits images of objects (stationary or moving) between distant points

Other hypernyms of colour television include television system.

colour television (noun)	television (noun)
a television that transmits images in color	a telecommunication system that transmits images of objects (stationary or moving) between distant points
	an electronic device that receives television signals and displays them on a screen
	broadcasting visual images of stationary or moving objects