So when the image switched to black and white, we see red-cyan's complementary colour.

因此，当图像切换为黑白时，我们会看到红色——青色的互补色。

Growing up, you likely learned about the primary colours red, yellow and blue-and their respective complementary colours.

在成长过程中，你可能会了解三原色——红色、黄色和蓝色以及它们各自的互补色。