They were colored the same, the backbones were colored the same in the diagram.

但颜色是一样的,在示意图这些主链的颜色是一样的

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That there are two colors per strut, so what's linking the two backbones together are two colored segments that come from the outside towards the middle, and that the colors occur only in certain combinations, red and green, yellow and blue, that's all you see.

每个梯阶有两个颜色,主链是由,两种不同颜色的片段由外向内连接起来的,这些颜色仅以某种特定方式配对,红连接绿,黄连接蓝,大家都能看到

耶鲁公开课 - 生物医学工程探索课程节选