[xoxxala]

Dogs can see some colors, but not as many as humans. They have dichromatic vision, and see shades of gray, brown, yellow and blue. Red and green are particularly bad colors for them.

We get blue tennis balls for our pups instead of green; but they aren’t the fetching kind so not sure if it helps.

[qwertfisch]

Regular tennis balls are yellow, why not just use these? (And are there really green tennis balls?)