So I need a little bit of help with arrays. I have created an array that will create ellipses when I click the screen. Though once they are placed I can't seem to do anything else with them. I have created a tracker that moves across the screen and I want it to change the colour of each individual ellipse separately as it passes it. I was wondering if this is possible and how would I do it? Any help would be appreciated thanks

int count = 1;
float [] xp = new float [count];
float [] yp = new float [count];
float [] s = new float [count];
float [] c = new float [count];

int range = 25;
int v = 255;
int b = 0;
int lx = 0;

void setup ()
{
  size (500, 500);
  background (0);
 
}

void draw ()
{
  gfx();
  tracker();
}

void mousePressed ()
{
  xp = expand(xp, count + 1);
  yp = expand(yp, count + 1);
  s = expand(s, count + 1);
  c = expand(c, count + 1);
 
  xp[count]= mouseX;
  yp[count]= mouseY;
  s[count]=random(5);
   count = count + 1;
 
}

void gfx ()
{

smooth ();
noStroke();
fill (v, v, v);
  int i = 0;
  while ( i < count){
    ellipse (xp[i], yp[i], s[i], s[i]);
   
//    yp[i] = yp[i]+1; //moving up
   
  i = i + 1;}
}

void tracker ()
{
  smooth ();
 stroke (0);
//  noStroke ();
  line (lx, 0, lx, 500);
  lx = lx+1;
  if (lx > 500){
    lx = 0;}
   
}