drab vs sorry

drab is a noun but sorry is not a noun.

Word	Noun	Adjective	Verb	Adverb
drab	Yes	Yes	No	No
sorry	No	Yes	No	No

As adjectives, drab and sorry are synonyms defined as:

Other synonyms of drab include blue, dark, dingy, disconsolate, dismal, drear, dreary, gloomy, grim.

drab (noun)	sorry (noun)
a dull greyish to yellowish or light olive brown

drab (adjective)	sorry (adjective)
of a light brownish green color	feeling or expressing regret or sorrow or a sense of loss over something done or undone
lacking brightness or color; dull	bad; unfortunate
causing dejection	causing dejection
lacking in liveliness or charm or surprise	without merit; of little or no value or use