Many people believe that dogs can only see in black and white with no ability to detect colours.
This is based on outdated research and has been disproved, but the range of colours a dog can see is different from humans.
Human eyes have three types of cones that allow them to detect colours, while dogs only have two. This means that dogs can mostly see shades of yellows, blues, and violets, while they cannot detect reds, greens, and oranges the way humans can.
This myth can cause misconceptions about how dogs perceive the world and may affect dog parents' decisions when it comes to training and figuring out which products to buy. Maybe when our next out shopping for your dog get them a yellow or blue ball that will show up more easily for your pup in the grass than a red one.
The good news is that dogs rely on their sense of smell more than their vision or other senses, so it shouldn't matter too much to your pup what you decide.
So that explains why some dogs get particularly agitated when workmen with yellow health and safety vests arrive at your house.