As dogs cannot tell the difference between red and green they have great difficulty in detecting a ginger cat on a lawn or against any other green background such as even foliage. Lawns are particularly effective. Dogs have been subjected to a colourblindness test designed for humans. They tested labrador retrievers, weinmaraners and Brittany spaniels and these dogs could not pick out a red cat running against a green background. The tests were carried out by scientists in Italy.
Dogs are colour blind. They have two kinds of pigment at the back of their eyes. One is for long and medium wavelengths of light which correspond to red and green. The other is for blue. The scientific study involved 16 dogs sitting between their owner’s legs and watching a film of a cat. The film footage was analysed to study whether the dogs took an interest. They barely reacted to a red (ginger) cat against a green background.
Does this make ginger tabby’s safer than any other domestic cat wandering outside? It well might mean that if the cat’s owner lives in a green and pleasant land such as England 😉 England is not that pleasant. Ginger tabbies are popular and ‘leaders’!
Source: Journal Royal Society Open Science.
I can’t argue with a careful test, though I’d like to read it, but I would assume that the red (or orange) cat would at least appear as a lighter shade of “green”, like various colors on a black and white photo appear as various shades of grey.