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What color toy should I get for my dog?
I recently got a dog and it loves to play fetch with toys. I know that dogs are color blind, but not like they see black and white, just less colors than humans see. I'm pretty sure any color toys will work, but what is the best color toy to get my dog? I need a color that the dog can easily distinguish from the colors around it, especially green (because of grass).
Dogs don't distinguish luminance (brightness) as well as we do, and have trouble telling red from green. The image below is the best comparison I've found of how we see vs. how they see, against different backgrounds. Websearching "dog color vision" found it, and a great deal of additional data.
comparison of how toys appear to us vs. to dogs, against both light carpet and grass http://www.lovingpawsllc.com/uploads/Articles/2009056.jpg
Dogs are not color blind. Instead of perceiving levels (intensity) of 3 colors like us (red, green and blue) they only perceive the intensity of two color: blue a

Dogs don't distinguish luminance (brightness) as well as we do, and have trouble telling red from green. The image below is the best comparison I've found of how we see vs. how they see, against different backgrounds. Websearching "dog color vision" found it, and a great deal of additional data.
comparison of how toys appear to us vs. to dogs, against both light carpet and grass http://www.lovingpawsllc.com/uploads/Articles/2009056.jpg
20170717 11:40:25 
Dogs are not color blind. Instead of perceiving levels (intensity) of 3 colors like us (red, green and blue) they only perceive the intensity of two color: blue and yellow. For example red is perceived as different levels of gray. Dogs have a kind of "redgreen color blindness".
So I'd say that blue and yellow are the easiest.
I don't know if it makes a big difference but I'm using pure blue and yellow only for my targets.
20170717 12:00:12 
They can see blue and yellow, all the other colors appear as shades of those two, especially yellow. Red appears browngrayish, violet actually appears as very vibrant blue, try to buy yellow and blue toys, I think it will make them happy that their toys don't appear dull
20170717 12:31:02 
If you just want to be safe, I would get a regular blue colored toy. Any colors like green, yellow (some yellows are fine if vibrant enough), and orange will be slightly more difficult for your dog to find in grass. Blue is very distinct and your dog will find it more easily, especially if they have any eye problems. Cyan (bluegreen) and magenta appear more whitish gray so if you would like one of those colors, they're also different from how dogs perceive green, thus easy to identify!
20170717 13:08:14