The categories, the colors, very quickly start to make sense when you just start poking around.

类别，颜色，当你刚开始移动它们,的时候就能进行这个了。

哈佛公开课 - 计算机科学课程节选

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