VANDENBERG AIR FORCE BASE, Calif. (AP) _ The twilight test launch of a Minuteman 2 missile produced a spectacular aerial display visible in four states as fading sunlight reflecting off the missile's wake tinted the sky blue, red, yellow and turquoise.

The light show Wednesday evening prompted thousands of calls to military officials, weather forecasters, sheriff's departments and radio and television stations in California, Nevada, Utah and Arizona.

''My phones have been going nutso,'' said Barbara Stringham of KONY in St. George, Utah. ''People were asking, 'Did they plan this for Halloween?'''

''We've been getting calls that are never ending,'' Airman Darryl Gehly said with a chuckle from Vandenberg Air Force Base, about 120 miles northwest of Los Angeles.

The launch was the 126th in a series of such tests, and ended successfully with the Minuteman's landing on target in the Pacific Ocean, the Air Force said. The missile reached the Kwajalein Pacific Missile Test Range, 4,200 miles southwest of the California coast, about a half-hour after it was launched, said Air Force Capt. Tom Connell.

The timing of the launch, just before 6 p.m., produced the brilliant light show, Gehly said.

As the missile rose into the atmosphere, unburned particles of rocket fuel left in its wake froze, Gehly said. Then sunlight reflected off the frozen particles, illuminating the darkening fall sky.

He added that such a phenomenon occurs frequently, but this one was apparently much more spectacular than most.

In Los Angeles, the launch captivated motorists for miles along Pacific Coast Highway and on freeways crossing the San Fernando Valley northwest of downtown Los Angeles.

Law enforcement agencies and radio stations in southern Utah, as well as the National Weather Service in Salt Lake City, reported receiving dozens of calls from mystified residents.

The weather service received so many calls it issued a statement advising its bureaus the lights likely were caused by the Vandenberg launch, said lead forecaster David Carpenter in Salt Lake City.

He said the bureau had learned that people in Utah, Nevada and parts of Arizona had witnessed the display.

Ms. Stringham said residents reported seeing colored lights that ranged ''anywhere from a white, foggy type to blues, greens, reds and oranges.''

''It was a bright, glowing light, giving off a vapor trail,'' said Bev Efishoff of Napa, in northern California. ''It went behind a cloud and then didn't come out. But the big glow remained.''