Working my way through the WPF/E QuickStart I stalled out when I hit a color Fill value of:
"sc#1, 0.8123474, 0.8123474, 0.8123474".
I didn't have to stall out there, but it bugged me that I didn't know what that was all about.
It took me a bit to find out that was "scRGB", but then I was able to find lots of pages about that.
I've written a short blurb about it on my site here:http://www.wynapse.com/WPFE/scRGB_Color_Reference.aspx