colour in vs blackwash

colour in is not a noun while blackwash is a noun.

Word	Noun	Adjective	Verb	Adverb
colour in	No	No	Yes	No
blackwash	Yes	No	Yes	No

As verbs, blackwash is a hyponym of colour in; that is, blackwash is a word with a more specific, narrower meaning than colour in:

colour in (noun)	blackwash (noun)
	a wash that colors a surface black
	a mixture of calomel and limewater that is used on syphilitic sores
	an attack intended to ruin someone's reputation

colour in (verb)	blackwash (verb)
add color to	color with blackwash
	bring (information) out of concealment