Hello David: Dirty desert sand, or dirty yellows, reds and oranges similar to shot with Fuji Velvia. Try a polarizer with less response to green/cyan. Maybe Rodenstock HR Digital super MC or Digital pro MC. If you want to see the difference try with two captures of the classic ColorChecker or Passport with and without polarizer filter and will see the difference of dE and how it charges over the green channel. I do that with ACR Calibrator Script (Thomas Fors/ Rags Gardner) and will surprise how calibration tab is altered by the calibration script. I know the work is well done by Eric Chan and Thomas Lianza, but I can't see numbers with DNG Profile Editor, that I use for approachings starting with the ACR camera profile, the more updated ACR version that can afford. But this is not your issue. ACR Calibrator Scrips likes EV15: 1/125, f16, ISO 100. Jose Bueno