colour TV vs color television system

colour TV and color television system both are nouns.

Word	Noun	Adjective	Verb	Adverb
colour TV	Yes	No	No	No
color television system	Yes	No	No	No

As nouns, colour TV and color television system are synonyms defined as:

colour TV and color television system: a television that transmits images in color

Other synonyms of colour TV include color television, color TV, colour television, colour television system.

colour TV (noun)	color television system (noun)
a television that transmits images in color	a television that transmits images in color