The word "colourise" refers to the act of adding color to something, often a black and white photograph, to give it a more vibrant and lifelike appearance. However, there are many antonyms for the word "colourise," including "bleach," "decolorize," "fade," "discolor," "pale," and "blanch." These words refer to the process of removing or reducing color, making something appear less vibrant or colorful. While "colourise" is often used in the context of restoring or enhancing something, these antonyms convey a sense of deterioration or loss of vibrancy. Nevertheless, they serve as useful alternatives in situations where the goal is to remove or reduce color rather than enhance it.