red vs spectral colour

red and spectral colour both are nouns.

Word	Noun	Adjective	Verb	Adverb
red	Yes	Yes	No	No
spectral colour	Yes	No	No	No

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

Other hypernyms of red include chromatic color, chromatic colour, spectral color.

red (noun)	spectral colour (noun)
red color or pigment; the chromatic color resembling the hue of blood	a color that has hue
emotionally charged terms used to refer to extreme radicals or revolutionaries
the amount by which the cost of a business exceeds its revenue

red (adjective)	spectral colour (adjective)
(especially of the face) reddened or suffused with or as if with blood from emotion or exertion
of a color at the end of the color spectrum (next to orange); resembling the color of blood or cherries or tomatoes or rubies
characterized by violence or bloodshed