I don't know the difference between the yellow w/ a red X and the white w/ a red X. Obviously they both indicate a missed call, but what does the yellow/white mean?
I had os 4.5 before 6, so the white icon is new to me.
Green = placed
Blue = received
Yellow = missed
White = missed call and then view the history of that missed call. The icon changes from yellow/orange to a white icon with a red x.