I really must be losing my mind.  I was changing the color of some components in an assembly model today.  Worked great!  Then, later I went to do the same thing.  WTF??!  Why can't I change the color of components??  Oh, I'm in a sectioned view.  But, wait, I swear I was in a sectioned view when I colored the other components earlier.

Well, this begs the question - Why can't I change component colors when in a sectioned view (in an assembly model)? 

Anybody else experience this problem?