Wiktionary
colourise
vb. 1 (context UK English) (alternative form of colorize nodot=1 English) (gloss: to add colour to). 2 (context UK photography filmology English) (alternative form of colorize nodot=1 English) (gloss: to convert black and white media to color by digital post production).
WordNet
Usage examples of "colourise".
Like an old black-and-white movie that’s been colourised, and not quite true.