Venetian red vs reddish brown

Venetian red and reddish brown both are nouns.

Word	Noun	Adjective	Verb	Adverb
Venetian red	Yes	No	No	No
reddish brown	Yes	No	No	No

As nouns, Venetian red and reddish brown are synonyms defined as:

Other synonyms of Venetian red include burnt sienna, mahogany, sepia.

Venetian red (noun)	reddish brown (noun)
a shade of brown with a tinge of red	a shade of brown with a tinge of red