I have one tea that uses Green Rooibos, it is pretty yummy. I don't know the difference between the two.
http://en.wikipedia.org/wiki/Rooibos
OK so:
Rooibos is grown only in a small area in the region of the Western Cape province.[2] Generally, the leaves are oxidized, a process often, and inaccurately, referred to as fermentation by analogy with tea-processing terminology. This process produces the distinctive reddish-brown colour of rooibos and enhances the flavour. Unoxidized "green" rooibos is also produced, but the more demanding production process for green rooibos (similar to the method by which green tea is produced) makes it more expensive than traditional rooibos. It carries a malty and slightly grassy flavour somewhat different from its red counterpart.