Colourising old photographs is the banal apotheosis application of diffusion AI.
It's the pinnacle of the whole thing: "imagine it for me in a way that conforms to my contemporary expectations".
If you're going to colourise images, have the decency to do it by hand. If possible on a print with brushes.
Edit: didn't think this would be popular. Maybe it's the historical photography nerd in me, but colourising images without effort and thought is like smashing vintage glass windows for the fun of it: cultural vandalism.
I think a lot of it depends on what you are doing and why.
Yes, recolors can be inaccurate but they can make historical moments feel more alive and connected. At the same time one can imagine the issues of a recolor that is inaccurate and that is troubling with historical photographs.
At the same time I have a bunch of old family photos I'd love to recolorize. Maybe the colors won't be quite right but that's an OK failure mode for family photos!
I'd love to see a version where you can drop just a spot or two of the correct color and let the AI fill it out. My grandmother had stark red hair but most algorithms will color her as a blond. It'd be nice to fix that, using one of the color photos we do have.