Many RV's use the standard mini-blinds which are available almost anywhere. We've bought some inexpensive ones at WalMart and Target, and more pricey and durable ones from Home Depot or Lowes.
FWIW, Lowes carries some blinds that are very, very similar to the stock ones in Keystones. Take a close look at what you have on other windows and then make a trip to Lowes or Home Depot. You may not get a precise color match to what you already have, but I am betting you will find something that you will be really happy with for many years.
Our Cougar has the blinds that have an opaque section and a translucent section for varying conditions. You can sort of see through the translucent section from the inside out, but they give pretty good privacy the other way.
'11 Cougar 326MKS loaded with mods
'12 Ford F250 SuperCab 6.7 PowerStroke Diesel
KD2IAT (146.520) GMRS:
WQPG808 (462.675 TPL 141.3)