I agree with you, I prefer lighter interiors.
The Arctic Fox we bought is moderately dark inside, darker than I would like but not as dark as some brands in recent history.
Even though it was darker, we have found that it isn't all that bad in most camping situations where it's sunny. OTOH if we're in a heavily tree'd CG with lots of cover, we turn on lights even though it's bright out. We didn't have to do that with our old TT with a natural oak finish.
If you're like us, you'll find that you can live with a bit darker interior if you like everything else about the RV.