They are linked together by four different colored segments indicated here not by colors now but by letters.

它们由四个不同颜色的片段连接,这里不是用颜色表示,是用字母表示

耶鲁公开课 - 生物医学工程探索课程节选

It's the phosphate and the pentose that make up the backbone - that make up the upright struts of the ladder and it's the bases that make up the connecting struts, so the bases are the colors.

磷酸基和戊糖,共同构成了主链,主链又构成了梯子上下的支柱,而碱基,则构成连接支柱的梯阶,碱基是用各种颜色表示的

耶鲁公开课 - 生物医学工程探索课程节选

So let's -- we'll go to a brand new color, TS define A as u minus TS.

我们用一种新的颜色，定义A等于u减去。

麻省理工公开课 - 热力学与动力学课程节选

Where before it was two colored pairs now it's two lettered pairs .

之前用两种成对的颜色表示,现在是用两对字母GCTA表示

耶鲁公开课 - 生物医学工程探索课程节选