Not sure if this is strictlt GQ, but do dopers have any idea? My own hair is what I think is black but I have had people tell me its “dark brown”.
Is there a tangible difference or is it just perception. The latter I think.
Well, dark brown hair is brown, while black hair is black, which is a different color than brown. That is probably the biggest difference between the two, they are different colors:). I think I know what you mean. I have dark brown hair that could appear to be black until I stand next to my brother, who has black hair, then you can see the difference in the contrast. Same thing when I am looking for matching navy or black socks in the morning. The navy sock looks black until I hold it against a black sock, then I start to percieve the blueness of it.
There are also certainly people who insist only certain ethnic groups can have black hair and if you aren’t one of those groups then no matter how dark your hair is it can’t be black, only very very very very very very very very very very very very very very very very dark brown.
Look at these pictures. The first two are identical in colour yet one is labelled “black” the other “drak brown”. The third is a tiny shade lighter and is apparently “brown”.
Can you really not see the shade variations in those three pictures? To me all three are quite different and labelled correctly. As the second poster stated - black hair is black, brown hair is brown. If your hair is dark brown, it is brown not black.
OB
Yeah, the third looks much much lighter. The first two are pretty similar but where the light is catching it, it looks dark brown as opposed to black.
Look at the hair with sun shinning through it.
In a lightless room, all hair is black. 
Truly black hair would appear black no matter how much light you’re in.
Well, even black hair looks slightly brown/red with strong backlight… but all the same, I am one of those people who insist that only certain ethnic groups can have truly black hair. I’ve never seen a white person with hair that didn’t have some colour to it, for instance. Even “black” (read: very dark brown) is pretty uncommon.
Sweet! So we all can save money on that jet black hair dye by spending more time in lightless rooms. Nice.
You can notice the difference in bright sunshine. And it’s not just with humans . . . one of my cats appears to be solid black, but when he’s in the sun reddish highlights appear.
I have to agree - they all look distinct to my eye. It could be that you just have a slight difference in color perception compared to most, which would not be that uncommon.
Natural sunlight brings out the nuances in color. I had a stylist once who, before dying my hair, stood out in the sun with me for a minute to see what colors were being reflected off of it (or something like that). It was the most natural dye job I’ve ever had. It looked so great and not artificial or anything.
…or your screen settings need improving, of course. If there’s one thing I learned as a web developer, it’s never to trust another user’s interpretation of colour unless they’re sitting at your machine.
So I must have red-blond-brown-black hair since those are the colours that come out when I stand in the sun (in increasing frequency).
Yes 1 is shinier than 2 and 3 has reddish highlights. Except for the shinier part no I can’t see and difference between 1 and 2.
Maybe you need to adjust your monitor. I can clearly see that Monica Bellucci’s hair is dark brown in that pic-- really dark, but nonetheless definitely brown. My hair is the same shade as hers, and my driver’s license has always said “Brown.”
I’ve never heard the thing about certain ethnic groups and black hair before, but it sounds prima facie silly to me. I’m very, very tempted to ask for a cite to a scientific study of it.
I definitely have dark dark brown hair, which looks black in some lights, but there’s lots of highlights in it. There is a clear difference.
My ex-wife, my oldest daughter, and I have the same shade of hair that is labeled “Dark Brown” in that picture. All of us have gotten comments from people that our hair is black when it clearly is not. Some people really can’t tell the difference between really dark brown hair and black hair or so it seems and I always found that odd.
I have the dark dark brown hair, too, but I can’t really tell the difference myself. I guess because I’m usually not looking at in a certain light–I just see myself in mirrors usually indoors. I’ve had people tell me it looks dark brown, though…and others who think those people are crazy. To make things easier on people I haven’t met, I just say it’s black.
How’d you respond to my hypothesis that the differences in what you call brown or black may be cultural? For example, my haircolour to another Nordic (perhaps even to a Middle European) is a medium brown (at least it’s called medium brown in the colour charts.) Not so around the Mediterranean, where people see me as blonde. Since black hair used to be so rare hereabouts, we may be less sensitive to nuances in the upper reaches of the Baltic region. Sort of, if it’s darker than a wood dinghy treated with coal tar, it’s black.
The most stringent definition I’ve heard focuses on the colour of your highlights in the sun. Black hair has blue highlights according to this, and if the highlights are red, it’s brown.