Gen. Colin Powell, the first black to be chairman of the joint chiefs of staff, will be an honorary grand marshal for a parade to honor Martin Luther King Jr. in Atlanta on Jan. 21. But some black leaders, such as the Rev. Joseph Lowery, president of the Southern Christian Leadership Conference, had opposed Powell's selection because of King's dedication to non-violence and denouncements of militarism. "While I have a great deal of admiration for Colin Powell, under the present circumstances I have deep concern," Lowery said. "I think it creates an awkward set of circumstances that neither a King holiday nor General Powell ought to have to face."