discolor vs bleach

discolor is not a noun while bleach is a noun.

Word	Noun	Adjective	Verb	Adverb
discolor	No	No	Yes	No
bleach	Yes	No	Yes	No

As verbs, bleach is a hyponym of discolor; that is, bleach is a word with a more specific, narrower meaning than discolor:

discolor (noun)	bleach (noun)
	the act of whitening something by bleaching it (exposing it to sunlight or using a chemical bleaching agent)
	the whiteness that results from removing the color from something
	an agent that makes things white or colorless

discolor (verb)	bleach (verb)
change color, often in an undesired manner	make whiter or lighter
lose color or turn colorless	cause to become white or lighter in color
cause to lose or change color