light brown vs beige

light brown and beige both are nouns.

Word	Noun	Adjective	Verb	Adverb
light brown	Yes	No	No	No
beige	Yes	Yes	No	No

As nouns, beige is a hyponym of light brown; that is, beige is a word with a more specific, narrower meaning than light brown:

Other hyponyms of light brown include tan, topaz, dun, fawn, grayish brown, greyish brown, ecru.

light brown (noun)	beige (noun)
a brown that is light but unsaturated	a very light brown

light brown (adjective)	beige (adjective)
	of a light greyish-brown color