Why West colonize & exploit Africa ok, but West attack China trade w/ Africa?

why is it the West had unjustly colonized, exploited the resources, enslaved the peoples and oppressed Africa for generations with impunity, even for decades supporting racist White rules in South Africa and Rhodesia, but now the Western politicians, media and activists keep attacking China which is not stealing but just trading with Africa and investing there? From Africa to Tibet to the non-political Olympics, why is the West so vociferously anti-China in visceral biases and unfair attacks? Chinese peoples worldwide in diaspora and those in China are amazed at all these double-standards