I think you're confusing Deng with Chen Yun (who was another high-ranking Chinese communist party official who was also anti-cultural revolution and pro-market socialism):

Had Mao died in 1956, his achievements would have been immortal. Had he died in 1966, he would still have been a great man but flawed. But he died in 1976. Alas, what can one say?

Deng's assessment of Mao was more positive:

We will make an objective assessment of Chairman Mao’s contributions and his mistakes. We will reaffirm that his contributions are primary and his mistakes secondary. We will adopt a realistic approach towards the mistakes he made late in life. We will continue to adhere to Mao Zedong Thought, which represents the correct part of Chairman Mao’s life. Not only did Mao Zedong Thought lead us to victory in the revolution in the past; it is — and will continue to be — a treasured possession of the Chinese Communist Party and of our country. That is why we will forever keep Chairman Mao’s portrait on Tiananmen Gate as a symbol of our country, and we will always remember him as a founder of our Party and state. Moreover, we will adhere to Mao Zedong Thought. We will not do to Chairman Mao what Khrushchov did to Stalin.

We must make a clear distinction between the nature of Chairman Mao’s mistakes and the crimes of Lin Biao and the Gang of Four. For most of his life, Chairman Mao did very good things. Many times he saved the Party and the state from crises. Without him the Chinese people would, at the very least, have spent much more time groping in the dark. Chairman Mao’s greatest contribution was that he applied the principles of Marxism-Leninism to the concrete practice of the Chinese revolution, pointing the way to victory. It should be said that before the sixties or the late fifties many of his ideas brought us victories, and the fundamental principles he advanced were quite correct. He creatively applied Marxism-Leninism to every aspect of the Chinese revolution, and he had creative views on philosophy, political science, military science, literature and art, and so on.

I would be quite content if I myself could be rated fifty-fifty in merits and demerits. But one thing I can say for myself: I have had a clear conscience all my life. Please mark my words: I have made quite a few mistakes, and I have my own share of responsibility for some of the mistakes made by Comrade Mao Zedong. But it can be said that I made my mistake with good intentions. There is nobody who doesn’t make mistakes. We should not lay all past mistakes on Chairman Mao. So we must be very objective in assessing him. His contributions were primary, his mistakes secondary. We will inherit the many good things in Chairman Mao’s thinking while at the same time explaining clearly the mistakes he made.

His view of Mao's actions was said to be "70 percent right and 30 percent wrong." This was similar to his view of Stalin:

To use the Chinese way, the score for Stalin would be thirty percent to seventy percent: thirty for his errors and seventy for his merits. Furthermore, Chairman Mao agreed with me on the question of Stalin’s score, and, after the twentieth Congress of the CPSU, members of the Communist Party of China expressed a very clear judgment of Stalin. We said that we would always continue to consider his writings as classic works of the international Communist movement.