Code coverage coloring used to be green, blue, and red.  In recent builds I suddently noticed it's more of a blue/purple/red type of color scheme.  This is hearsay, it may or may not have any grounding in fact.  But I overheard in the hallway the other day mentioning that in usability studies people saw the green and shifted their focus just towards the red code as if green code were good.  But obviously just because it was covered doesn't make it good code.  And they didn't know what the blue meant.  Now the colors are less emotionally charged and also the purple-ish color can represent a mix between the two areas to help the user understand it is partially covered.