It's not "colourised". It's common for people to feed original artwork into generative AI to produce an AI slop version for some reason. Then they show it to the original artist and tell them it's an "improved" version.
Nikki (she/her/it) ΔΘ🦮DONT PUT MY ART INTO A FUCKING GENERATIVE AI PROGRAM; DON’T SEND IT TO ME ACTING AS IF YOU’VE IMPROVED MY ART… YOU DIDN’T!!!!! This is the THIRD FUCKING TIME this has happened. Holy shit I’m fucking LIVID