how to blink a texture till there is a mouse click on it

Hi,

I have two textures. one is the actual texture of the object and the other is the texture with highlight color on the actual object texture. I want the highlight texture to be On/Off (like a blinking effect), to indicate the player to click on the object. once the player clicks, the actual texture remains and the highlight texture is turned off.

 void OnGUI ()
 {
     GUI.DrawTexture(new Rect(0, 0, 100, 100), originalTexture);
     GUI.DrawTexture(new Rect(0, 0, 100, 100), highlightTexture); // 
     
     //turning the highlightTexture ON & OFF will make it look like an indication for the player to click on it //?????
 
     if("player clicks on the area of this texture") // I am getting this value from the mouse click position
          //then remove highlightTexture and have only the originalTexture //????
 }

how do I get this effect. Helpppppp!

Thanks in Advance :)