Dyed in the Soul : INDIGO, <i> By Richard Wiley (Dutton: $19; 272 pp.)</i>

Indigo is a deep blue, a sometimes sad but always powerful blue, charged with feeling and hope. Richard Wiley’s new novel “Indigo” weaves the color indigo--and the whole idea of color--into a brilliant tapestry of human diversity. Body color, mind color, dyed-in-the-soul color, Wiley makes us see it, wear it and finally smell it in all of its sweet and stinking shades. Color is everything, this important novel tells us, because color is how we perceive ourselves.

Jerry Neal serves as the novel’s loom-shuttle protagonist, batted back and forth between ever-tightening threads of the story. Recently widowed, Neal runs the International School in Lagos, Nigeria, with earnest efficiency. It is this honest enthusiasm--his school- teacher temperament--that lands Jerry Neal in trouble.

In the affluent United States, schoolteachers may be losing esteem, but in developing countries the profession commands respect. Governments often will allow American teachers to teach the children of the countries’ elites, even if what the children learn undermines their parents’ cultures. American teachers are thus the honored and ingenuous agents of cultural change, intelligent yet unwitting. At the story’s beginning, Jerry Neal is clearly intelligent, although he is not yet wise.

After investigating a series of petty thefts of copy-machine fluid, and then being accused of a far greater crime, Neal is himself stolen, spirited away by dissidents planning a coup. Their plans for Neal are manifold. They want him to be their hostage, their comrade and their dupe, all rolled into one.

While “Indigo’s” plot line is tightly controlled, its direction always seems wide open. During Neal’s abduction, Nigeria is revealed as a fascinating morass: Freeway off-ramps plunge into lakes of mud; in a great Lagos market, “De finance business be near de monkey business,” which sells caged and suffering monkeys. This market--as well as Neal’s future--seems to have so many entrances and passages that, to Neal, it looks “more like a door store” than anything else. His kidnapers offer him even more possibilities, including political, philosophical and sexual union. He resists, considers, hesitates and even scolds and advises the rebels.

He tries his American best to understand. At one point, he stands looking at a sensuous indigo cloth designed by the equally seductive artist Sondra: “It was a beautiful thing, open and enticing, and it made Jerry want to step in.” Can Neal ever wholeheartedly join them? Can a Westerner ever really connect with the rest of the world?

“Indigo” knots up and then unravels culture and color, and braids them back into intelligible patterns. It examines culture’s effects on our perceptions of skin color, and on all our learned perceptions of other people and ourselves. Indeed, the term color here refers more to a quality of feeling than to some visible physical attribute. Wiley goes beyond the gray-scale politics between the West and “the rest,” beyond the black and white of face-to-face race relations, and he plunges deeply beneath his readers’ own skins. By its end, “Indigo” does more than transcend color. It transmutes color, and finally--literally--it makes color itself disappear.

With “Indigo,” Wiley further secures himself a place among America’s finest writers. His “Soldiers in Hiding” won the 1986 PEN/Faulkner award for best American fiction, with its vivid portrayal of a Japanese-American caught in Japan by the bombing of Pearl Harbor. His “Festival for Three Thousand Maidens” told the tribulations of a Peace Corps volunteer teaching in a Korean village. This newest novel continues Wiley’s examination of the clash and communion of cultures, but it also breaks new ground.

In ways, “Indigo” recalls Graham Greene’s Africa novel “The Heart of the Matter,” with its intrigue, bureaucracy, confusion and despair. Richard Wiley is as fine a storyteller as Greene was, and in “Indigo,” Wiley may go Greene one better in the way he puts so much humanity into a single symbol--color--and then washes it through his entire story.

“Indigo” is both a novel of ideas and an essay of actions, with unembellished but powerful prose and quietly spoken anxieties. Wiley has made the color indigo into his heart of darkness. Indigo encompasses us all. Still, there is hope in that heart, as on the day artist Sondra says to Neal, “Indigo comes in all de shades. And indigo life be de richest one, das what I believe.”