You can make the flag itself different colors and use the same setting as recommended.  I have pictures uploaded with black/white, gray/light gray, and dark gray/light gray, all with the same layer settings. 

Project: Air Force Hueforge.hfp

Print at 100% infill with a layer height of 0.08mm with a base layer of 0.16mm

The Model is 200x200mm in size

You may print at higher layer heights below the Base Thickness of 0.72mm
The Max allowed Thickness is 2.48mm and the Actual Thickness is 2.26856mm

    #8c9099 PLA PolyLite Grey  Transmission Distance: 1
    #d1d3d5 PLA BambuLab Basic Light Gray  Transmission Distance: 1.7
    #00358e PLA BambuLab Basic Blue  Transmission Distance: 4
This print uses 3 unique filaments

Swap Instructions:
    Start with Grey
    At layer #12 (1.04mm) swap to Light Gray
    At layer #18 (1.52mm) swap to Blue for the rest.