The mellow voice of Zimbabwe's most popular black television newscaster did not hesitate nor did her expression change as she talked about the "liberation war against colonialism."

For Mandy Mundawarara, however, it must have been incongruous. The daughter of Silas Mundawarara, the deputy prime minister in the discredited administration of former prime minister Abel Muzorewa, was calling her father's former government a colonial regime.

Its most hated opponent, guerrilla leader Robert Mugabe,is now called "comrade prime minister." Just a few months ago his name was banned from the media, and he could only be referred to as a "terrorist leader."

Thus in one small way has Rhodesia become Zimbabwe.

Mugabe, doing a balancing act between risking black expectations and continuing white fears, has moved slowly since taking power April 18. The use of "comrade" and the not-so-subtle attacks by the state-owned broadcasting system on the previous white government seem to be a signal to both camps that changes are on the way.

In a sense, the newly renamed Zimbabwe Broadcasting Corp. controlling radio and television has simply replaced one master for another, neither highly receptive to the idea of Western-style press freedom.

A senior white broadcasting source, who served under Muzorewa and the white government of former prime minister Ian Smith, said matter-of-factly, "We are a servant of the state. We will be expected to reflect the government viewpoint as thoroughly as under Smith." He said he thought the amount of control would be about the same as before.

The source noted sardonically that the white staffers who are complaining about news management by two Mugabe party loyalists now ensconsed in the newsroom never complained in the past about similar tactics by the white government of Smith.

"People agreed with that censorship; now they don't agree, so their ethics are involved," the source said. He said white-controlled Rhodesian broadcasting served its public about as well as its counterpart in the Soviet Union and that "we used the same techniques, too." He cited frequent one-sided stories.

"Only a liar would say morale here was good," the source said, adding that he expected two or three of the 14 whites on the news staff to leave. There are five blacks, all in the lowest positions, on the newswriting staff that serves both radio and television.

Even those who resent the new government, however, admit that the situation has not been as bad as they expected, he said. After an initial period of suspicion and doubt on both sides, relations between the staffers and the "media advisers" from Mugabe's Zimbabwe African National Union party have settle down. Both sides have given ground when differences have arisen, according to the source.

Probably the key area where the ZANU influence has been felt is in commentary and feature programs rather than in news broadcasts.

The radio recently ran a commentary on the 14th anniversary of the April 28 "famous Sinoia battle when the first shots of liberation were fired."

The official chronology of events published by the former white-run Ministry of Information neglected any mention of this "famous battle" almost 100 miles northwest of Salisbury in which seven ZANU guerrillas were killed after unsuccessfully attempting to blow up a power line.

The commentary said the guerrillas were fighting "colonialism, imperialism and oppression." The words hardly brought joy to whites, who had been told by their previously censored media that the guerrillas were battling for communism.

The new minister of information Princeton-educated Nathan Shamuyarira, said in an interview that the news media previously were used as a "propaganda machine to attack [the government's] enemies. . . .We want to change this entirely" so the broadcasts provide a "service to the broad masses."

The ZANU party workers had been brought in, he said, "to persuade our colleagues to reflect more accurately the new order."

The government wants to "make it clear that criticism is not prohibited," the minister said. He cited numerous critical letters in the The Herald, the country's main independent daily. All criticism, however, must be within the limits of loyalty to the state, he added.

Shamuyarira himself has been the victim of previous interpretations of loyalty to the state. His book, "Crisis in Rhodesia," is technically still banned by the ministry he now heads.