Revealing mistake: The "Old man-ghoul" changes appearances drastically throughout the entire movie. In some scenes, it is Bela Lugosi in vampire cape, in others it is the famous "double" who is a head taller than Lugosi, a lot thinner and has a different hairstyle. He covers his face with his cape, but this does not help a lot...
Revealing mistake: After Clay finally has been killed, you can still see him breathing, and even blinking his eyes.
Revealing mistake: Why are all of the space ships the same exact size as the planet?
Revealing mistake: The inside of the spacecraft is populated with electronic equipment sitting on tables. You can easily identify a Hallicrafters short-wave receiver which the alien tries to smash on Jeff Trent's head. In the B&W version, you can even see manufacturer labels on the front of the units. They are missing in the colorized version.
Revealing mistake: In the cemetery, you can see the actors' shadows on the fake sky.
