Two handsome and instructive shows of Africa's arts went on view yesterday at the National Museum of African Art, 318 A St. NE. Both are sharply focused. One is about color. The other deals with clay.

Both shows dare to teach. That is their chief virtue. Though buyers in the West--responding to the beautiful, the mysterious and the strange--have avidly acquired artifacts from Africa since Picasso was a youth, too often they have done so in a state approaching ignorance. They bought what pleased their eyes, not what they understood.

We still view works of tribal art--figurines and masks, weapons and utensils--through many veils. We may appreciate their power, but we do so from a distance. We rarely know their dates, or their complex, layered meanings, or how these things were used in dances, or what spirits they contain. Because African art scholarship is still relatively primitive, so, too, is our viewing. Both of these exhibits fight our mental blur. By asking us to concentrate on two of many attributes--not on magic or the afterlife, but on color, on material--they invite us to examine their artifacts from scratch.

Why is that piece of kente cloth from Ghana made of silk that's yellow? Why is that mask half black, half white? Why is that black Fang statue shiny while the one beside it is just as black, but matte? "African Art in Color," a 67-item loan show organized by Roslyn Adele Walker, the museum's curator, was designed to raise such questions, though the answers that it offers are often imprecise.

Though the yellow of that yellow cloth suggests gold and great wealth, a single color may, of course, hint at many things. Blue, for instance, in the West, may signify despair (the blues), or the sky, the sea, the Virgin, or the Yale football team. Something of the sort applies as well in Africa. Red, the red of blood, is frequently associated with the rites of death. "The Akan people," Walker writes, "wear red cloth while in mourning and a red substance is used to prepare the corpse for burial . . . Following a period of mourning, the Ashanti of Ghana exchange their red cloths for white adinkra cloths, joyously marking the deceased's arrival in the spirit world."

Angels, in the West, tend to wear white robes. So, of course, do ghosts. To the Yoruba of Nigeria, white symbolizes purity and divinity. To the Zulu of South Africa, white (meaning transparent) is a color linked to the Lord-of-the-Sky. The explanatory labels, and the objects on display, reinforce each other. One begins to understand why that kneeling funerary figure from the Yombe people of Zaire has been painted white. That color calls to mind both the ashenness of death and the holy cleanliness of the life to come.

Black, too, has many meanings, some positive, some negative. It may be used to call to mind the hue of living skin and the fertility of earth, but at other times it also hints at illness and at death. While the lustrous black surface of that guardian figure from Gabon suggests health and power, the dull black masks worn by members of the "Night Society" of the Bangwa people of Cameroon suggests what westerners might call the powers of the dark.

Three colors tend to rule the arts of sub-Saharan Africa. Often they are used in complex combinations. They are red, white and black.

On the basis of cave paintings, historians now believe that Africans have been employing body paint for 7,000 years. And 2,000-year-old painted bowls have been unearthed in Mali. But the pigments used most often--kaolin and chalk for white, red from ochre and from plants, black from charcoal, soot, mud and seeds--tend to flake away. Many antique artifacts, for instance Benin bronzes, once wore coats of paint that have been long since lost.

Walker has selected objects of great beauty. Some are rough, some intricate, some are clearly representational, others near abstract. One of the most impressive is an Ikenga from Nigeria, an elaborately carved figure whose colorings of black, white and yellow suggest power, bravery and wealth. These beaded cloths, and wigs, and pierced colored seeds, and masks dressed up with powerful red shotgun shells, all convey color messages. African art scholarship has yet to decipher all the many meanings that these hues express, but one leaves this exhibition knowing, without doubt, that there is a language there.

"From the Earth: African Ceramic Art," the second show on view, also asks us to see freshly. It was organized by Bryna Freyer and Edward Lifshitz. The clay objects they've selected have received much less attention than artifacts or bronze or wood, at least in the West. Many of these things--cooking pots and jugs and bowls--are utilitarian objects of elegant design. Others--figurines of fired clay, statuettes and heads--served symbolic uses. Only Benin chiefs collected statues made of brass. These clay heads from Benin were signs of lesser status displayed by the members of the brass-casters' guild. But some of the most memorable objects on display are both symbolic and utilitarian.

That fine hyena pipe from the Shilluk of Sudan has a bowl that sits upon the floor and a stem so long that its privileged smoker could enjoy his tobacco without rising from his chair. (The large clay pipes on view were used by men of status; women smoked the small ones.) A number of the finer pots included in this show have been elaborately strengthened, and decorated, too, with leather, basketwork and brass. One, a grand memorial pot from Ghana, probably contained a variety of relics--nail parings, hair, perhaps a piece of clothing--of some honored ancestor. Its clay figurative decorations--they show a game board and a ladder and a 19th-century brass clock--recite a sort of essay on the theme of death. The clock suggests the flow of time, the game board hints at chance, the ladder is a sign of an Ashanti proverb: "It is not only the poor man who climbs to death."

Though the pottery wheel has been used for centuries in North Africa, most sub-Sarahan pots are formed by hand, by women. Those in the exhibit range from tiny to huge. Some have the look of Art Deco, some seem Middle Eastern, others might, at first, be mistaken for Chinese.

This show's variety is great. Its workmanship frequently is stunning. Though these ceramics are not ruled by the red-white-black triad, their colors--dull grays, glassy greens, lustrous blacks, soft browns and tans--are no less impressive than those one encounters in the color show upstairs.

Both exhibits were installed modestly and handsomely by Lydia Puccinelli. "From the Earth" closes Oct. 9, "African Art in Color" on Oct. 16