又紅又專 means being both socialist-minded and professionally competent and this phrase used to be popular in China. Since the People's Republic of China is still a socialist country, why don't people use it anymore?
The color "Red" symbolizes "Blood", "Revolution". It has become the symbol of a Communist Region since the start of the Russian revolution, then it was imitated by the majority of the Communist countries, including China, whose country shared similar experiences politically and had followed the Russian's led.
However, after its relationship with the Soviet Union had severed and after Mao's death, the Chinese Communist Party no longer think the rigid communist doctrine is the feasible way for the party's survival, and in turn, now it fears the potential of internal unrest, due to widespread poverty and unsatisfaction, that could lead to another "revolution" and overthrow the ruling party. Thus, it has dropped many old political slogans/symbols that encourage people against the ruler and unfair treatment.
Now, China emphasizes improving the living standard and increasing/opening private wealth ownership for its citizen (more green - US dollar) rather than encouraging its citizen to "revolt" (thinking red and devoted to it) except for its party members, who, until now and foreseeable future, still hold the power to rule, to control, and to stir the direction of the country politically through the iron fist and the communist ideology.