I apologise in advance because I don't know if the movie in question is actually a movie, it could be a television series for all I know.

Anyway, on the TV show (hosted by Stephen Fry) "QI" Series F, Episode 9: "Future", they use a still of a man dressed in a silver suit and helmet and a woman in red from what I assume to be a sci-fi movie/television series when talking about why there are no time travelers if time travel hasn't been completely ruled out.

Here is the link to the YouTube clip of part of that episode - YouTube - QI Series F Episode 9 Part 1

The still occurs at around 6:44

Can anyone help me out?

Ok here is a link to a picture still taken from the QI episode with the man in silver and the woman in red used as a background (so you don't have to wait through 6 minutes of download):

http://www.flickr.com/photos/33503049@N03/3313789550/

I think it is "Sapphire and Steel"

"Sapphire & Steel" (1979)

I looked up Sapphire and Steel but I don't think it's that. Thank you though for the suggestion.