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

is this, kind of, green glass line in the middle of the pavement.

是一条在人行道中央的绿色线。

时间开始的地方 - SpeakingMax英语口语达人