Datagrid alternative row color based on band

Hi,

I want to color datagrid rows with alternate colors where the value in Column 'Name' changes
The data is not necessarily ordered by this 'Name' column,
the idea is that a group of adjacent rows with same Name value should have
same color but different than the adjancent band

1 Sam    (Yellow)
2 Sam    (Yellow)
3 Victor  (Blue)
4 Rohit    (Yellow)
5 Rohit    (Yellow)
6 Sam    (Blue)
7 John    (Yellow)
8 John    (Yellow)
9 Rohit    (Blue)
9 Victor  (Yellow)

Thanks,

-srinivas y.

sri