1、Humans are trichromats, meaning they have three types of color receptors in their eyes.
人类是三色视觉者，也就是说他们的眼睛里有三种类型的色彩感受器。
2、Some animals, such as dogs, are dichromats and can only see two primary colors.
一些动物，比如狗，是二色视觉者，只能看到两种主要颜色。