The lecture of Robert Simmon, a lead visualizer for the Nasa Earth Observatory, did not leave any questions unanswered. It demonstrated and answered questions regarding use of colours in a very scientific way. This is helpful for me. As a graphic designer I use a lot of "rules" demonstrated by Simmon, intuitively; probably through the experience gained working in visual communication.
However, personally, I am influenced by and enjoyed a swiss education in graphic design. A kind of doctrine as "if you cant convey the information in black and white, you are not finished" is deeply rooted in my approach to visual communication. I am still starting any project in black and white — and add color in a later phase, if necessary.
Simmons lecture poses the question for me personally, if thats still the approach to go or to start considering colors in an earlier phase.
On another note it was striking to see, how attracted I ( and supposingly others also) were by the handcolored visualization. Rich, "real" colors (still) have a greater impact on human than colors which are purely generated in pixels.
Another proof for it are the so often quoted cartographic maps (often swiss made). Their "sucess" is not only the very good design, but also the very good printing quality and the rich printing colors (due to a special printing process).
It shows that good/worthy "material" can have a greater impact when conveying information. The information designer Joost Grotens and his studio, as a contemporar example, puts great emphasis on actual good quality of material of their information design (http://www.joostgrootens.nl/#mapping)