Are all household pet cats color blind?

No, cats are not completely color blind. They can see some colors, but their vision is different from human vision.

Here's what we know about cat color vision:

* They are dichromats: This means they have two types of cone cells (the cells that detect color) in their eyes, compared to humans who have three.

* They can see blue and green: Cats can see shades of blue and green, but they likely can't distinguish between red and green very well.

* They have better night vision: This is because they have a higher concentration of rod cells (the cells that detect light) in their eyes.

So, while not entirely color blind, cats see the world in a different way than humans do. They may not see all the vibrant colors we perceive, but their vision is adapted for their hunting and nocturnal lifestyle.