Alternate coloring of cell rows with twist?

[GLOpro]

Hi,

I am looking for a method that would alternately color the rows but if the cell value was identical it would be the same.

ie:

1
2
2
3
4
5
5

Row 1 would be white
Row 2 & 3 would be grey (since they are the same cell value)
Row 4 would be white
Row 5 would be grey
Row 6 & 7 would be white



Part 2 of this:
Is there a formula that will calculate the sum of cells (for each series of same color rows?)
ie
Row 1 sum=1
Row 2&3 sum=4
Row 4 sum=3
Row 5 sum=4
Row 6 & 7 sum=10

Thanks in advance.