polychromize vs colourize

polychromize and colourize both are verbs.

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

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

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

polychromize (verb)	colourize (verb)
color with many colors; make polychrome	add color to