The campaign I am about to start has "Night Elves" which are a darker skinned variety that live underground. They are not 'evil' like the Drow, but do have a more cranky attitude to them (I described it as the inhabitants of the world attributing it to their proximity to the Dwarves )
To me, this is exactly what I mean. I have long detested the notion that ALL of ANY race (Drow, Orcs, Klingons, whatever) are ALL evil, or ALL sneaky and underhanded (Hobbits, Ferengi) or ALL good and wise (Elves, Vorlons).
In my world, I have a nation of beings physiologically the same as Drow, but sociologically different. They're extremely lawful, have a bureaucratic government, are quintessential traders, and practice a benevolent slavery (and a not-so benevolent eugenics program on 'inferior' races). However, I leave room for groups within this society for not just one, but many to disagree or even oppose some or all of these social conventions. There's even antisocial anrchists among them. It's the nature of things...
I think it would be interesting to have submissions on potential cultures for each race - like this one, the 'dark-skinned Elf' (which does not make evolutionary sense for an underground race - their skin would not need melanin, UV rays being somewhat rare in caverns...)
Then some sample societies:
DnD's Drow, living in groups of 1-6 in underground treasure-filled complexes with 500 Orcs and 10000 goblins,
Cory's Night Elves, living underground...
Sorloc's Dylari, living in, on, and under mountains...
If a sample society is produced by a few people for each racial type, there would be quite a wealth of stuff to go on.
I've got a desert Lizardman culture and a jungle Lizardman culture - physically identical, but ideolodically different...