artifact that I didn't really notice until watching the color enhanced Remastered "The Immunity Syndrome" was the color offset during the "vibration" opticals:
The red-blue split makes the images look like anaglyphic 3D. The screen cap above was pulled from the original DVD version, although I did amp up the color a bit to highlight the color offset. (I could not pull a cap from the TOS-R HD version, as I do not have it in my library. I could probably pull a cap from streamed Netflix, but I think everyone gets the idea.)
I'm guessing the "vibration" effect could have been done without the color offset, but someone might have thought it looked better.