Like Norman Rockwell before him, LeRoy Neiman has the distinction of being one of the very few American artists whose work is familiar to practically everybody in the country -- rich and poor, black and white, urban and rural, educated and illiterate. This is as far as their similarity goes, however. Rockwell, who died in November, 1978 at the age of 84, was known for his meticulously detailed, placid portraits of American family life, while Neiman has built his reputation on action-filled scenes composed of bold splashes of color. Rockwell's career started and ended at the _Saturday Evening Post_; Neiman's began at _Playboy_ and has reached its zenith in an entirely new medium -- television. His televised mural of the 1976 Olympic Games was seen by an estimated 170 million people. One of the most commercially successful artists in the world, LeRoy Neiman has spent the last 18 years living and working in a huge apartment/studio just off Central Park West. His original paintings command up to $50,000 each, but the larger portion of his work comes out in the form of limited-edition serigraphs (silkscreen prints). A single piece of silkscreen art generally yields some 300 prints, each of which sells for about $1,500. Neiman's eye-catching style is admired everywhere. His posters and calendars are best-sellers in Japan; several of his painting are on permanent display at the Hermitage Museum in Leningrad. He was the official United States artist-in-residence for the last two Olympics and will be for the 1980 Games as well. Although best known for his sports pictures, Neiman is also a renowned portraitist who specializes in famous faces. He is attracted by drama and excitement of any kind, whether found in a tavern inhabited by the Beautiful People, in a heavyweight fight, in a world chess championship, or, as television viewers witnessed last January, in a Super Bowl. Neiman sat on the sidelines of that contest drawing pictures of the game in progress, using a computer-controlled electronic pen and palette. The pictures were then flashed onto the television screen. "It's painting with light," explains Neiman one morning in his studio, taking a break from the half-dozen oils and acrylics he is working on. "It gives you the same sense of creation as any other art medium. You're building and creating an image of your own that wasn't there when you started. The only limitation you ever have in doing a work of art is yourself." Starting this month, Neiman's work has become a regular feature of _CBS Sports Spectacular_. At the beginning and end of each program, Neiman's paintings are interspersed with photographs of athletes to form a moving collage of colors and shapes. The artist has been contracted to make six or seven personal appearances on the program over the next year, in which he will demonstrate the art of drawing sports in action.