3D Animation of Texture in multiple Parts of an Arrow

Hello I am trying to animate an arrow, which is consisting of 25 parts. I want to loop through the parts and switch the texture on / off to animate it. I use OnMouseDrag() to move the arrow. And I tried to start a Coroutine to turn the texture on and off, with WaitForSeconds(). My question is, is this possible to make the arrow blink ?? I have to stop blinking by clicking on the arrow, because I want a value between a Min and a Max, which is representing by the color, to launch a Ball. The arrow is the "Speedarrow" to move this ball in a direction, with a speed.

I hope you can help me out and my English is not to bad.