Just got the PM saying i was needed, so...
I am not a genius when it comes to software like OO an i have little or no experience with OO3 but from what i can rember from OO2 it is done via setting the background to a light grey, if you are talikg each row or coloum has a shade an the other hasnt i have no idea I can look into it. Just give me a few to download OO3 and i will look into it for you.