This thread got me wondering.
I’m a red/aburn headed person so I have no clue. Where do you have to be skin shade wise to not buy any suntan lotion for a day at the beach on a sunny day in the middle of July?
Reference levels:
Andre Agassi
George Hamilton
Halle Berry
Bryant Gumbel
Jesse Jackson
Nat King Cole
Any skin colour can still get sunburnt, I believe, although many are more tolerant than others.
Here’s a rundown of various skin types and their ‘immunity’ to the sun.
Uh, I’m a lovely shade of brown and I can burn in less than 45 minutes sans sunblock. With sunblock, I can go a couple of hours in the sun, but I’d be smart to reapply. If I’m in the water, especially at a waterpark or pool, I’m going to burn no matter what.
I hate sunburns 
Anecdote:
When my mother was in high school, there was a group of black roofers working on a house in her neighborhood. It was a clear, hot day, and one of the workers laid out a towel on the grass, and took a nap.
I’m unclear how long he slept, but my mother reported that the fellow sustained severe sunburn. She described his complexion as “eggplant”, like Grace Jones.
Well, back in 1973 I spent the afternoon girlwatching with three white friends on Daytona Beach. They all got surnburned; I didn’t.
I got some good laughs out of that (they were good sports about it). Granted, in a few more hours I probably would have been sunburned, too; I was just lucky.
All I know is you have to be MUCH darker than me! I wear sunscreen every day when the sun’s out - even if it’s just walking to and from classes. Sometimes I STILL get sunburned!!!
Even with 65spf on, I’ll be burned within 30 minutes!
I read a webpage whose address has long since disappeared from my memory (sorry) that yes, any skin complexion will burn, and that no one is immune to sunburn. Trying to be accurate from memory, I think the SPF value of really dark skin - litterally black - was something like 8… so some people can go longer before betting burnt, but even this is not very much protection at all.
Perhaps a lot of the darker skinned people are in less develloped places where sunscreen is more of a luxurey, and they do get sunburns but it’s so common and just part of life that they don’t realize it. I can’t picture an African bushman out trying to hunt gazelle putting on his suntan lotion in the morning and keeping track of how many hours he’s been out in direct light.
Tanning in the sun (aka burning) has been around a lot longer than sunscreen, so lots of people don’t realize or care about the dangers of UV light - but everyone is vulnerable given enough exposure.
I am not really familiar with all the people that you suggest as reference points, so I can’t really answer as you suggest. But I can say from personal experience that those that suggest one can not be brown enough to not burn are just plain wrong.
I’m white. As far as any of my female ancestors are prepared to admit (:)) my ancestors are Irish/English/Scottish, whatever that means. But I do tan pretty easily.
Back in my sailing days I built up a tan (not on purpose, it’s just the way it worked out) starting in the North Atlantic and working south. By the time we reached the Carribean, I could spend the entire day in full sun with my shirt off no problems at all.
“Black” people can burn, but I think you’d find that they would only do so if they had not had much exposure to sun in a while. I have an Indian friend who once managed to get burnt, but only because he spent an entire day in the sun at the beginning of summer, having not had his shirt off for six months. Ordinarily he never burnt and used to laugh at us “honkies” who did.
WARNING I live in Queensland, Australia. It is the skin cancer capital of the world. I spent my whole childhood outdoors with no protection. I get checked regularly, and the fact that I tan gives me a better chance than someone with very pale skin. BUT the mere fact that you are not burning does not mean you are not being hit with UV, and your chances of getting skin cancer are, IIRC, proportional to your total exposure to UV.
So it may be possible to tan enough not to burn, but that doesn’t mean it is a good idea.
I recall some years ago a West Indian cricketer on tour remarked in an interview that the Windies players had to be careful about sunburn in Australia although it was no problem at home.
According to Biological Perspectives on Human Pigmentation by Ashley Robins, people of any skin color can burn. Having very dark skin by itself provides a sun protection factor (SPF) of 13.4, and fair skin is equivalent to SPF 3.4. A person with very dark skin and no sunblock should be able to stay in the sun almost 4 times longer without burning than a fair-skinned person with no sunblock.