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One can use a diffuser of a different color, but this is not recommended. All Top LEDs should be enabled to improve uniformity of the illumination.
Proper usage of diffusers with all Top LEDs turned on
ViBox mirrors should be removed or covered up with some reflective material which do not change light spectrum. One can use white paper for this task. But it is important to make sure the paper don't have any color tint. You can take a picture of the paper located near a white patch of the color target and make sure they have the same color tint.
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Good image of ColorCheckerSG
Good image of Munsell 5Y page
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