If you have any black and white images laying around, you can have some cheap (actually free) entertainment by allowing a website-based artificial intelligence system colorize your photos.
I tried a few of my own photos, and as you might expect, the results are mixed. At best, the site (quickly) gives a decent-looking "imagining" of what the photo should look like; at worst, it looks like a bland sepia-toned print.
It does not alter the original image on your computer, you just upload it to the site for almost instant processing and then you can save the colorized result if you wish by right-clicking on the image and selecting "save image as".
It seems to work best if you have something that the neural network AI can "guess" correctly - blue sky, green grass and the like. Below is a photo taken by yours truly in the 1970's, and the colorized result - not terrible.