Tracking an animated ball - actionscript-3

Question

In this project I am trying to track a ball. If the balls color is grey I want it to be surrounded with a square. My Problem is that there is only a ball being tracked. I would like all the grey balls to tracked.
Would really appreciate if someone can help me out.
Here is the code(Ball and Box are called from an external class):
package {
import flash.display.Sprite;
import flash.events.Event;
import flash.geom.Point;
[SWF(frameRate='31')]
public class Main extends Sprite
{
private var balls:Array;
private var directions:Array = [new Point(-1,-1),new Point(0,-1),new Point(1,-1),
new Point(-1,0),new Point(1,0),
new Point(-1,1),new Point(0,1),new Point(1,1)
];
private var ballNum: Number = 10;
private var ball:Ball;
private var ball2:Ball;
private var box:Box;
private var ay:Number = 5;
private var gravity:Number = 6;
private var bounce:Number = -0.9;
public function Main()
{
init();
}
private function init():void
{
balls = new Array();
for(var i:Number = 0; i < ballNum; i++)
{
ball = new Ball(Math.random() * 30);
ball.x = Math.random() * stage.stageWidth;
ball.y = Math.random() * stage.stageHeight;
ball.direction = directions[Math.floor(Math.random()*directions.length)];
addChild(ball);
balls.push(ball);
}
box = new Box();
addChild(box);
addEventListener(Event.ENTER_FRAME, onEnterFrame);
}
private function onEnterFrame(event:Event):void
{
for(var i:int = 0; i < balls.length; i++)
{
balls[i].x += balls[i].direction.x;
balls[i].y += balls[i].direction.y;
}
if(ball.color == 0xcccccc)
{
box.x = ball.x - box.width / 2;
box.y = ball.y - box.height / 2;
}
}
}
}

Answer 1

You have only one box and one box can have only one x and y after onEnterFrame function ends.
try something like this:
for (var i: int = 0; i < balls.length; i++) {
balls[i].x += balls[i].direction.x;
balls[i].y += balls[i].direction.y;
if (balls[i].color == 0xcccccc) {
box[i].x = balls[i].x - box[i].width / 2;
box[i].y = balls[i].y - box[i].height / 2;
//OR balls[i].box.visible=true;
}
}

Answer 2

You need to put your check for color in the for loop to check all your balls:
for (var i: int = 0; i < balls.length; i++) {
balls[i].x += balls[i].direction.x;
balls[i].y += balls[i].direction.y;
if (balls[i].color == 0xcccccc) {
box.x = balls[i].x - box.width / 2;
box.y = balls[i].y - box.height / 2;
}
}