The name Sudan comes from "bilad al sudan": Arabic for "the land of the blacks."
So you might expect Sudanese to be comfortable with the color of their skin. But they're not.
"They are equating black with dullness, so a black person is stupid, automatically a slave," says southerner Agnes Silver Nyarsuk. She explains that Southern Sudanese consider themselves black, while northerners see themselves as Arabs – and treat blacks as second class.
"For transport, an Arab lady when she enters, the men will stand up and give the place, for an Arab lady, because she's a woman," Nyarsuk says. "But a black lady, even if she is old, and she's shivering, dying, they will not respect because you are automatically a slave."
The differences between north and south might seem like one of religion but that's only a secondary conflict. Most northerners are Muslims. And most southerners follow traditional African religions or Christianity.
Sudanese journalist Godfried Victor Bulla has written extensively on race issues. He says even when northerners and southerners are the same religion, perceived racial difference keeps them apart.
Black or Arab?
"An Arab looks at a black southerner, despite the fact that he's a Muslim, they look at him as inferior," Bulla says. "Someone, you know you're nothing. It has never been that a black southerner is a sheik. This attitude grows bigger."
In South Africa's Apartheid system of racial division, the white power structure was easy to see. Sudan's Apartheid isn't so clear cut. If the president of Sudan, Omar Al Bashir, were to walk down a street in Washington DC, he'd be considered black. But Bulla says not in Sudan.
"Bashir is an Arab, Bashir is not black," Bulla says. bashir is a chocolate kind of color, it's a color which is not black totally," says Victor Bulla.
Retired southern Gen. Joseph Lagu says that what the Sudanese have been fighting is "Arab racism, apartheid in the Sudan."
He led the first armed resistance against the north in 1963. He says Institutionalized racism is what led southerners to war against their northern neighhors. He blames the 19th century British war hero, Lord Horatio Kitchener, for the racist attitudes held by northern Sudanese even today.
"The racism which the British brought, Kitchener planted it here, divided the people in the in 4 catagories," says Lagu.
A tiered system of racism
The top category was the white race, represented by Kitchener and the people he brought followed by the Arab Egyptians who made up much of his army.
Category three were the Sudanese working as porters and servants. And at the bottom were black southerners. So it's logical that the post-independence elite who have ruled the country since 1956 see themselves as Arabs.
"They associated themselves and identified themselves with Arabs, although they are not accepted by the Arabs," Khartoum-based analyst Albaqir Muhktar says. "But they claim to be Arabs, they are not really Arabs, they are nubians, and indigenous people of Sudan have been Arabized, in a way that that their language become Arabic and religion becomes Islam, that's all. But their looks remain Africans."
Mukhtar says Sudanese people have a wide spectrum of skin colors – and concepts of skin color to match.
"And we describe the color of a northerner who is very black, we call him green," says Mukhtar. "Although two different people, one northerner and one southerner, having the same color, when we describe the southerner we call him black, bluntly. When we describe the northerner, they call him green."
Mukhtar says that North Sudanese rarely admit there's such things as racism, so the mentality will likely persist for the foreseeable future. But with South Sudan set to officially declare independence in July, the north will have to deal with southerners as a sovereign country – and not an internal minority.
And that will be key to future stability and relations between the two states.