blackwash vs colour in

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

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

As verbs, colour in is a hypernym of blackwash; that is, colour in is a word with a broader meaning than blackwash:

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

blackwash (noun)	colour in (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

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