The OP doesn't state which car he is adding power steering fluid to. It makes a difference.
For the 2015, look for Pentosin CHF 202 white can. Pentosin is not really generic but it is readily available at NAPA and costs less than VW's product. 202 is 100% synthetic oil as is the equivalent spec VW product.
A4 chassis cars can use basically any synthetic ATF in the power steering
mine's been in there for the last 6 years and 60-70k miles, and it is still nice bright red as compared to the CHF that had drained out dark brown rather than the nice bright green that it comes as