White vs white woman

White and white woman both are nouns.

Word	Noun	Adjective	Verb	Adverb
White	Yes	No	No	No
white woman	Yes	No	No	No

As nouns, white woman is a hyponym of White; that is, white woman is a word with a more specific, narrower meaning than White:

White (noun)	white woman (noun)
a tributary of the Mississippi River that flows southeastward through northern Arkansas and southern Missouri	a woman who is White
a person of European descent with a light-skinned or pale complexion
United States educator who in 1865 (with Ezra Cornell) founded Cornell University and served as its first president (1832-1918)
United States writer noted for his humorous essays (1899-1985)
United States architect (1853-1906)
United States political journalist (1915-1986)
Australian writer (1912-1990)
United States jurist appointed chief justice of the United States Supreme Court in 1910 by President Taft; noted for his work on antitrust legislation (1845-1921)