That's because the color receptors in your eye aren't very light-sensitive, and only the brightest stars can trigger them.

这是因为你眼睛里的颜色感受器对光线不是很敏感，只有最亮的星星才能触发它们。

When one of these color receptors doesn't function correctly, a person loses the ability to see that part of the color spectrum.

当这些颜色受体中的一个不能正常工作时，人就会失去看到光谱中这部分颜色的能力。

This is one of the two major theories psychologists have proposed to explain how we can see so many colors despite having only three kinds of color receptors in our eyes.

这是心理学家提出的两个主要理论之一，用来解释什么我们的眼睛只有三种颜色感受器，但我们却能看到这么多颜色。

In the same way that we mix primary paint colors to create a whole palette of color, the combination of these three types of color receptors allows us to see a wide spectrum of light.

就像我们混合原色来创造出整个调色板的颜色一样，这三种颜色受体的组合使我们能够看到更广的光谱。