Stormy won't play with anything else if he has seen on of these. Dogs actually see the blue one better than the orange one. If you have a dog who will find it no matter what, blue is best. Less confident and need to see it yourself? The orange is easy to spot even if it's a little muddy. Great bounce, 2-3 times as much as any tennis ball. Stand up to chewing 2-3times better than normal tennis balls too. But not recommended to leave down with a heavy chewer all the time. We love the whistle effect, guides us both in the direction it went. Easy to throw a million times with a chucker.