i am trying to get a code that will let the line scroll through and change the color. i would like to get it to filter through several colors and so far I have a basic code picked out, I can get it to draw in a new color but is there a way to tell it that since it's now teal, it has to draw red, etc.

float a = 100;

void setup()
{
 size(500, 500);
 background(255);
}

void draw()
{
  stroke(95, 158, 160);
  a = a - 0.5;
  if (a < 0) {
    a = height;
   }
  line(0, a, width, a); 

 
}

This is what I have so far and I am having trouble making the bars rely on w/s and up/down arrows


// Global variables for the ball
float ball_x;
float ball_y;
float ball_dir = 1;
float ball_size = 15;  // Radius
float dy = 0;  // Direction
float heeto = 0;
// Global variables for the paddle
int paddle_width = 10;
int paddle_height = 60;
int again_width = 10;
int again_height = 60;
int dist_wall = 15;

void setup()
{
  size(640, 360);
  rectMode(RADIUS);
  ellipseMode(RADIUS);
  noStroke();
  smooth();
  ball_y = height/2;
  ball_x = 1;
}

void draw()
{
  background(51);
 
  ball_x += ball_dir * 1.0;
  ball_y += dy;
  if(ball_x > width+ball_size) {
    ball_x = -width/2 - ball_size;
    ball_y = random(0, height);
    dy = 0;
  }
 
  // Constrain paddle to screen
  float paddle_y = constrain(Cheeto, paddle_height, height-paddle_height);
  float paddle_2 = constrain(Cheeto, again_height, height-again_height);
 
 
  // Test to see if the ball is touching the paddle
  float py = width-dist_wall-paddle_width-ball_size;
  if(ball_x == py
     && ball_y > paddle_y - paddle_height - ball_size
     && ball_y < paddle_y + paddle_height + ball_size) {
    ball_dir *= -1;
    if(mouseY != pmouseY) {
      dy = (mouseY-pmouseY)/2.0;
      if(dy >  5) { dy =  5; }
      if(dy < -5) { dy = -5; }
    }
  }
  float p2 = dist_wall+again_width+ball_size;
  if(ball_x == p2
     && ball_y > paddle_2 - again_height - ball_size
     && ball_y < paddle_2 + again_height + ball_size) {
    ball_dir *= -1;
    if(mouseX != pmouseX) {
      dy = (mouseX-pmouseX)/2.0;
      if(dy >  5) { dy =  5; }
      if(dy < -5) { dy = -5; }
    }
  }
 
  // If ball hits paddle or back wall, reverse direction
  if(ball_x < ball_size && ball_dir == -1) {
 
  }
 
  // If the ball is touching top or bottom edge, reverse direction
  if(ball_y > height-ball_size) {
    dy = dy * -1;
  }
  if(ball_y < ball_size) {
    dy = dy * -1;
  }

  // Draw ball
  fill(255);
  ellipse(ball_x, ball_y, ball_size, ball_size);
 
  // Draw the paddle
  fill(153);
  rect(width-dist_wall, paddle_y, paddle_width, paddle_height);
  fill(153);
  rect(dist_wall, paddle_2, again_width, again_height); 
 
}