The presentaton that stood out to me was by Liam Mason from Marine Scotland and makes up the bulk of the rest of this post. His presentation was on 'Improving Accessibility in Data Visualisation':
"Rainbow colour schemes are commonly used in data visualisation, particularly in climate science & meteorology. Liam will demonstrate how these colour scales can distort, mislead, and confuse your message, and offer some advice on how to improve your use of colour."
Not only did he effectively demonstrate what colour blind people would see in different GIS scenarios but also supplied useful web links to where resources are supplied for avoiding these pitfalls. Apparently 1 in 12 men and 1 in 200 woman are affected by colour blindness in the world.
I thought I would end this post with a list of some colour blind resrources to help make colour blind friendly maps.
Vischeck - simulates coloublind vision
Colorbrewer 2.0 - has a colorblind safe option
Color Oracle - a colour blindness simulator for Windows, Mac and Linux
It's also worth noting that since QGIS 2.4 offers color blind and greyscale simulators.