Two press photographers belonging to the Maoist Revolutionary Communist Party of the U.S.A. poured cans of red paint over the American and Soviet ambassadors in the Security Council chamber today.

This evenhanded demonstration by members of the group, which disrupted the White House welcome for Chinese Deputy Premier Deng Xiaoping 15 months ago, occurred just as the council was settling down to a U.S. veto of a resolution affirming the right of the Palestinian people to "establish an independent state in Palestine."

The victims, shaken and splattered but otherwise unharmed, were Soviet Ambassador Oleg Troyanovsky and the American deputy representative, Ambassador William vanden Heuvel, who were chatting beside their council seats.

The assailants were identified by a U.N. spokesman as Keith Kojimoto and Steven Yip, both accredited as photographers for the Chicago-based Revolutionary Workers and thereby eligible to mingle with the diplomats on the floor until the meeting started.

Hustled off by U.N. guards, the pair shouted: "Our flag is red, not red, white and blue; down with Soviet-American war moves." The United Nations said it would press charges of trespass and malicious assault. u

Kojimoto was acquitted of similar charges one year ago in Washington after the shouting demonstration interrupted President Carter's welcome for Deng on the White House lawn.

Troyanovksy remained in the council conference room, waiting for a change of clothing. Vanden Heuvel emerged, red from neck to thigh, telling reporters that "It was just one of those things one encounters in diplomacy these days."

The assailants, he said, "were shouting something about war. When they got me, I thought they were for it. When they hit Oleg I thought they were against it."

The resolution vetoed tonight by the United States was similar to one in 1976, supported then by the French. This time, Britain, France, Norway and Portugal abstained while seven Third World countries, the Soviet Union, China and East Germany voted in favor.