I would prefer the brighter screen on the right, that's how my Oasis is also. I have 3 Voyages and only one is sepia like the one on the left on pic. It's true the screens on all of the Kindles will vary in color temp. I still kept the sepia Voyage, the screen clarity is good and it works well. That's pretty much my criteria for screens.
I read anywhere from 12-15 light level on all my devices.