discoloration vs discolouration

discoloration and discolouration both are nouns.

Word	Noun	Adjective	Verb	Adverb
discoloration	Yes	No	No	No
discolouration	Yes	No	No	No

As nouns, discoloration and discolouration are synonyms defined as:

discoloration and discolouration: the act of changing the natural color of something by making it duller or dingier or unnatural or faded

As nouns, discoloration and discolouration are synonyms defined as:

Other synonyms of discoloration include stain.

discoloration (noun)	discolouration (noun)
the act of changing the natural color of something by making it duller or dingier or unnatural or faded	the act of changing the natural color of something by making it duller or dingier or unnatural or faded
a soiled or discolored appearance	a soiled or discolored appearance