There's a common misconception that dogs can only see in monochrome and use varying brightness levels to identify the outlines of items.
Yet Russian scientists have now proved not only do dogs have a limited colour range, they use this visual spectrum to distinguish between objects and select certain items from a line-up.
Previously, dog trainers would avoid using coloured objects when training pets to do certain tasks, but these findings could improve how animals are trained and what they are capable of learning.
A team of researchers from the Laboratory of Sensory Processing at the Russian Academy of Sciences tested the sight of eight dogs of varying sizes and breeds.
They wanted to expand on the work from the University of Washington last year.