mottle vs colourize

mottle is a noun but colourize is not a noun.

Word	Noun	Adjective	Verb	Adverb
mottle	Yes	No	Yes	No
colourize	No	No	Yes	No

As verbs, colourize is a hypernym of mottle; that is, colourize is a word with a broader meaning than mottle:

mottle: mark with spots or blotches of different color or shades of color as if stained
colourize: add color to

Other hypernyms of mottle include color, color in, colorise, colorize, colour, colour in, colourise.

mottle (noun)	colourize (noun)
an irregular arrangement of patches of color

mottle (verb)	colourize (verb)
colour with streaks or blotches of different shades	add color to
mark with spots or blotches of different color or shades of color as if stained