Cape Verdean President Aristides Pereira pointed to his hand, the color of light chocolate, to explain his country's recent bitter split from former sister nation Guinea-Bissau on the mainland and account for the assassination eight years ago of Amilcar Cabral, the venerated father of both countries independence.

The relationship of Cape Verdeans and Guineans, even while fighting together against the Portuguese, Pereira said, "has been a problem of skin color."

The deeply sensitive division surfaced in November in Guinea-Bissau when indigenous Guineans overthrew what they claimed was a discriminatory government dominated by lighter-skinned, mestizo Cape Verdean immigrants and their descendants who had evolved into an urban elite during colonial days.

The assassination of Cabral and the coup, Pereira contended in a recent interview, were the peculiar legacies of Portugal's skin-color caste system imposed on the jointly administered colonies until independence. Only six years old as a nation, this 10-island, poverty-stricken nation is living up to its reputation for toughness vy confronting that colonial legacy while fighting to build up economic self-sufficiency in the midst of the longest drought in recent memory.

Portuguese sailors discovered the then-uninhabited islands in the 15th century when they were blown off course while searching for the Cape Verde Peninsula on the African mainland. The islands form a 1,500-square-mile horseshoe of practically barren, reddish volcanic rock and rocky soil pushing straight up from the Atlantic Ocean floor, but the misnomer stuck. Cape Verde became a resupply station for ships and a transit point during three centuries of the flourishing Atlantic Ocean slave trade.

Indigenous blacks were taken from Guinea to the islands to work on Portuguese plantations or in transit to Brazil and the Americas. Few Portuguese women had come with the settlers, and the result was extensive sexual mixing between Portuguese slave masters and Guinean women.

The offspring were stratified by the Portuguese in a caste system based on skin shades, the lighter skinned being the most favored. The caste system was exported into Guinea when the better-educated Cape Verdeans were recruited by the manpower-short colonial government to work as civil servants.

In 1956, Cape Verdean Pereira; Amilcar Cabral; his brother, Luis; and three other men founded the African Independence Party of Guinea-Bissau and Cape Verde (known by its Portuguese acronym, Paigc). When anticolonial war broke out in 1963, no fighting took place on the Cape Verde islands, but many islanders joined the struggle and fought alongside Guineans on the mainland against the Portuguese Army.

Amilcar Cabral, the most charismatic of the leaders, was born in Guinea in 1924 of a Cape Verdean father and Guinean mother but was educated in Cape Verde. He returned to work in the Guinean colonial administration in the 1950s after receiving an agronomy degree from the University of Lisbon.

"During the war, the Guineans were used more in the fighting than the Cape Verdeans," claimed Guinean Mario Cissoko, who was interviewed in Bissau. "There were also numerous instances of the Guineans revolting against the impositions of the Cape Verdeans."

Pereira said the Portuguese colonial and military authorities were able to use the caste-born animosities between Guineans and Cape Verdeans to involve Guineans in a plot to assassinate Amilcar Cabral in nearby Conakry, now the capital of the Republic of Guinea, in 1973. His Guinean compatriots killed him "as a Cape Verdean leading Guineans," said Pereira. They participated in the plot "in the racist sense of Cape Verdeans against Guineans, Guineans against Cape Verdeans," a weakness the PAIGC movement has never been able to overcome, Pereira concluded.

Although last November's coup was aimed at uprooting alleged Cape Verdean influence and former president Luis Cabral is still in custody on vague charges of corruption and abuse of power, most immigrant Cape Verdeans remained in Guinea. A major reason for reluctance to return to the islands is economic.

In Sao Jorge, a village on the main island of Sao Tiago, the hardy creole peasants have watched a cruel replay year after year since 1968. They hopefully plant their seed corn on the steep hillsides of the harsh, volcanic landscape. After the July rains begin, the stalks sprout straight and green during several weeks of violent downpours. Then, before the corn's ears begin to form, the rains end abruptly and the plants wither.

"If it happens again this summer, it'll be our 13th year of drought," said Horacio Soares, director of Sao Jorge's new agrarian research center.

The Cape Verdean farmers, six years after independence, are today hard at work manually building up the country's economic potential in the face of almost impossible odds. Foreign experts working in Cape Verde said that with a 25-year nonstop development effort concentrating on land reform, irrigation and expansion of the fishing industry, Cape Verde will eventually be relatively immune to the ravages of cyclical droughts that have periodically decimated the islands' population for hundreds of years.

The survivors of a six-year drought during World War II can still recall scenes of mass burials, infanticide, family suicide pacts, and interior villages virtually depopulated by famine.

Those desperate sights have not been repeated this time, although the present drought is already twice as long. Thousands of tons of food and $40 million in annual development assistance have poured into the country since its 1975 independence.

"Our agricultural possibilities are limited," said President Pereira. Only about 20 percent of the country's 1 million acres of land is cultivable, and even with a return of normal rainfall that is insufficient cropland to feed the present population of just under 300,000 people, he said.

But development officials believe that by tripling the country's annual 10,000-ton fish catch and quintupling the lobster catch of 100 tons the export of those products alone could pay for imported food needs.

To create a profitable fishing export industry, however, will take millions of dollars in harbor improvements, onshore refrigeration facilities, and replacement of the traditional threeman longboats with modern trawlers.

Five years of irrigation projects have opened up only 700 additional acres for farming -- bringing the total of irrigated land up to a small 4,900 acres. Part of the difficulty is the slow replenishment rate of the groundwater used for irrigation because of the drought.

Now the islanders, men and women, are spending the long dry season building rock catchment dams by hand. The dams stop the rapid runoff of rainfall into the sea and allows the water to slowly percolate into the hard surface, replenishing the groundwater. The dams, the construction of which is financed with a $3 million annual grant from the U.S. Agency for International Development, have also reduced the erosion of precious top soil and the alluvial deposits that build up behind the dams are being used to grow crops.