Lots of people think that dogs see in black and white. But this is not true. Scientists recently discovered that dogs do see colors, just not quite the same colors that we do.

When people see a rainbow, they see purple, blue, blue-green, green, yellow, orange, and red. But when dogs see a rainbow, they see gray, blue, gray, yellow-brown, yellow, and yellowbrown. Can you imagine?

Dogs see red and green as a single color (yellow-brown) and also blue-green and purple as a single color (gray). This means that if you buy your dog a bright red toy, it will see it as an ugly yellowish brown.

Why? Well, a human eye has three different types of cells that can detect color. Dogs' eyes, however, have just two. This makes the range of colors that they can pick up much more limited.

很多人認為狗狗只看得見黑色和白色，但事實並非如此。科學家近期發現狗狗看得見顏色，只是和我們認知的顏色不同。

當我們看見彩虹時，看到的是紫色、藍色、靛青色、綠色、黃色、橙色、紅色。但當狗狗看見彩虹時，牠看到的是灰色、藍色、灰色、黃褐色、黃色與黃褐色，你能想像嗎？

狗狗將紅色和綠色視為同樣的顏色（黃褐色），將靛青色和紫色視為同樣的顏色（灰色）。這代表了如果你幫狗狗買了一個鮮紅色的玩具，牠看到的會是醜醜的黃褐色。

這原理是什麼呢？ 因為人類眼睛以三種不同的細胞組成來感應色彩，狗狗卻只有兩種細胞，因此狗狗的眼睛能看見的色彩範圍有限。