A red light means get into position. Yellow light means ready.

VOA: standard.2009.09.10

It's no use talking about the negative relationship between a red light and a green light and a yellow, white, or blue one because they all have the same value.

讲什么它是红灯，不是绿灯,不是黄灯白灯一点关系都没有,它们所代表的意义都一样。

耶鲁公开课 - 文学理论导论课程节选

Now in a stoplight, it only has three, one is tempted to say, variables plainly differing from each other: red, yellow and green we have two ways of thinking about the red light.

交通灯，三种灯，红黄绿，它们的颜色和彼此不能,我们有两种方式认识红灯的意思。

耶鲁公开课 - 文学理论导论课程节选

"It's putting a false sense on the market right now that everybody has this big flashing yellow light flashing, caution,caution,caution, so people are buying stuff you know in high volume than they usually buy.

VOA: standard.2010.05.08