It's your choice: lilac, magenta, violet, lavender, pomegranate and plum. I am especially in love with that grey/purple color that is out there right now. Purple is huge for s/s 10 and I definitely see it rolling over into Fall 10. We are sure to see deep deep purples for Fall 10.
For S/S 2010 you can't go wrong with accessorizing in purple. Think purple leather shoulder or cross body bag. It looks great paired with an all black or grey monochromatic outfit. Oh and don't get me started on purple heels. So cute against black skinny leg jeans!