Colorized movies in the 80's really looked like crap. They couldn't deal with complex scenes very well. I saw crowds splashed all with one color, or as in the case of "The Nutty Professor", left in B&W while the foreground characters were in color. Note the background in the NOTLD VHS shot isn't colored in at all.

It's a tad better now in that it looks like some weird faded real color at times. The only place where I've seen it really work well is in old cartoons. Warners had a bunch of early Looney Tunes shorts colorized, but they don't seem to play on Cartoon Network these days.

Colorization has been used to restore bits of a Doctor Who episode where the color couldn't be recovered with the other methods they've used, so I no longer regard the process as a tool of the devil as much as I used to. ;)