I also passed a colour blindness test (just for factory shop floor work but some tasks involved wiring) but I don’t think that makes any difference. I think that as we age, we tend to need greater contrast to read. I’d guess that what might look quite readable to a younger editor could be a bit harder for me.

I’d guess another factor with print could be the lighting used to view the document. A “daylight white” might bring the contrast out better than a “warm white”.

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This seems more focused on designing an app as the main example but some might find this interesting.