I have 4 black Indy jackets of various hides and manufacturers, and wear them just like the brown ones while trying to stick with a black belt and shoes, and sometimes black jeans, too.
Other than a little coordination with belt/boots, I see no distinction. And, some say that strict coordination with your other leather accessories isn't even really necessary. I believe the military mixes brown and black leather gear with no regard to color.
In fact, as a motorcyclist, I grew tired of wearing the black 'uniform' so much, I seek out brown riding gear! Just got a Vanson Cap for that very reason.
I don't like longer leather jackets in general however. The length is where I get hung up. Leather isn't generally all that warm anyway, and doesn't make very good rain gear. Not a fan of car coats either, jmo. But I do like the Belstaff Panther, though.
A long, lamb skin coat can make a guy of any age seem like he's 'trying too hard', if I understand the general implication of seeming to need some attention or maybe appear a little pretentious. I'm not saying the long leather coats and overcoats aren't useful, just that I don't see them being very useful or practical to most guys today. The old German military long coats and u-boat commander coats are cool, though. JMO, YMMV, etc., etc.
I am 56 and I know, wear what you want, right? But I just don't want to send the wrong message, I have read on some forums that women think older men in black leather jackets are creepy or that they are trying too hard, especially when they wear them to a bar or out at night. I have also read that some people think brown leather screams "old man". So if I AM an old man what do I do? To add to the confusion, my daughter says get black, while one of the ladies at work says brown. I have clothes to go with both colors. My question is in reference to full quarter horsehide jackets and am thinking of going with a Lost Worlds Ryder in dark brown russet as a compromise, but they are too expensive to buy one of each. Don't say ask you wife; she would kill me if she knew I was even thinking about another leather jacket! Your thoughts? 
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Seriously, After bagging the brown Ryder, I may pick up a dressier, lighter weight black jacket. I would feel like a poser in a bike jacket, as I don't ride, so I doubt I could pull that off. Very sound advice CM 
