How do we know animals see in black and white?

How do we know their brains don't convert it into colour

Posted from TSR Mobile

Humans have three types of cone cells (the cells in your eye which can see colours). This enables us to distinguish between all the different colours we can see.

Different animals have different numbers of cone cell types. Butterflies have five, so they are better at distinguishing colours than we are. I don't know if there are any animals which see literally in black and white, but that would require them not to have any cone cells.

Dogs, which are often thought of as 'seeing in black and white' actually have two kinds of cone cell, so while they don't see as many colours as the typical human, they do not see in black and white. Here is an image demonstrating how dogs see:

That's good. To know finally I'm proved right. Although I did mean like how we can tell wjat colour something is in a black anf white film

Posted from TSR Mobile

We know what colour things are in black and white films because we know what colour they are supposed to be anyway. If you were shown a black and white photo of something which isn't necessarily a specific colour (like a balloon or something) you would be able to tell it was a dark or a light colour, but you wouldn't be able to say if it was (say) dark green or dark red.

A dog would not be able to add in colour information to which it does not have access. So it would never be able to see any more colours than the spectrum shown in the image because it is not able to detect other colours.