Are you positive that this RS6 is sepang ? I just ordered my sepang R8 and the pictures that i saw of sepang R8s look different than this RS6.The S5 is definitely not Nogaro. It looks like Sprint or maybe Sepang.
I wish I could see all of these colors in person. I have seen (own) Nogaro and Sprint blue. But when I order the R8 it will either be Mugello or Sepang, and I have seen neither. No photo or brochure color patch can really illustrate what these pearl effect colors look like in person. That was particularly true of Nogaro.
Edit: Here is the best example of Sepang I have found-