I notice that David Letterman (at least while I was watching him) always used blue colored cards at his desk, and Jon Stewart seems to use typewritten sheets on blue paper. Why?
From my limited television experience, I know that scripts are colour-coded as to what version they are. I’m assuming in the US, blue means final draft.
Blue paper is easier on the eyes under bright lights. That is what I was told on a tour of a local TV station.
Light blue also is easier on the cameras. This isn’t nearly as much of a concern with today’s solid-state camera sensors, but older tube-based cameras would “flare” or “blow out” on bright spots of white like mad.
Up until maybe 10 or so years ago, it was pretty much taboo for people to wear anything that was actually white. A light blue or pink blouse or shirt would come through as white to the home viewers without throwing the cameras and engineers into a tizzy.
With the technology where it is now, using blue cards or paper is about as much tradition as it is anything else.
It is still easier to get good flesh tones if there is not a bright white surface in the scene.
Just wanted to mention that I was curious about this subject, having seen the hosts on both tonight’s Daily Show and Colbert Report using notes on blue paper. So I went to Google, and this thread was the second hit that came up. Yay Straight Dope.