Moderate line on S. Africa reform

South Africa's Colored (mixed race) Labour Party will continue to negotiate with the white nationalist government over universal suffrage and seek peaceful solutions, its leader, the Rev. Allan Hendrickse, said Tuesday.

He told some 400 delegates at the party's annual congress in this northern Natal town it recognized that ''there is no single strategy for social change in South Africa.''

Mr. Hendrickse also said it was no denial of his party's principles to use the government proposals as a platform for further negotiations. The Labour Party wants a one-man, one-vote unitary system, but is prepared to negotiate on the basis of a federal structure, he said.

He was apparently replying to Zulu Chief Gatsha Buthelezi, who urged the Labour Party to reject government proposals.

''We will make our own judgments and will not be intimidated or browbeaten by either radical, irrational, or irresponsible elements in the black community, on the one hand, or by the government with its powers of persuasion, legislation, and security action on the other.'' He said the time for protest politics had passed.

Mr. Hendrickse paid a tribute to Prime Minister P. W. Botha for risking his leadership over reform plans which call for the sharing of white power with Coloreds and Asians. But he warned that the Labour Party could not identify itself with constitutional plans that did not take into account the great majority of South Africans - the blacks.