[pbhjpbhj]

It seems more likely a function of actual contrast in the real World than a function of bias (inadvertent or otherwise)?

I imagine it's down to skin tone, or do facial recognition systems really recognise dark skinned "Caucasians" better than light-skinned non-Caucasians.

[keanzu]

Exactly: In the extreme, perfectly black objects have no visible contrast whatsoever as demonstrated by Vantablack.

https://www.wired.com/story/vantablack-anish-kapoor-stuart-s...