Contrary to what most of us were raised believing, dogs can see in colour. Not the same as we see things, but similar.
Dogs are dichromats which means they have two different colour receptors (we have three). They see the blue/indigo/violet range and the yellow-green range (so that’s the Y G BIV part of the old ‘roy g biv’ mnemonic device.) What they lack (and what we have) is the RO or red/orange receptors.
And grey. It seems grey is the base colour in any creature that uses receptors to see.
So, dogs see in a couple of shades each of blue, and yellow/green and grey. They see red and orange as ‘green’, anything of a greenish blue as gray and they struggle to see purple.
And so now we know!
