blue water ball

For people who know something about the water walking ball, they may know that the color of water ball can be customized. It can be blue, red, pink, or any kind of color combination, as long as you can think of it. All of those colors can be used by the premise of the color should be crystal clear. Why is that? The simple reason would be that player being inside the water ball need to see through the ball to know which direction they should go, instead of going in blind or being under the potential of danger.