Bit more information here (page 20 onwards) for all you kit nerds.
http://www.fifa.com/mm/document/tournament/competition/51/54/30/equipment_reg_26032010_en.pdf
This is my favourite bit, just reading it makes my head really hurt.......
5.3 With the sole exception of vertically or...
I've heard that the new England Kit (yes, the new one launching less than 12 months after the last one) will have blue shorts, but white shorts will be worn in the World Cup.