color myColor = color(255, 0, 0);

void setup()
{
  size(600, 600);      // def. output resolution
  noStroke();
  background(255);
  fill(myColor);
}

void draw()
{

  if (mouseButton == LEFT) {
    fill(myColor);
     ellipse(mouseX, mouseY, 20, 20);
  } else if (mouseButton == RIGHT) {
    fill(255);
    ellipse(mouseX, mouseY, 20, 20);
  }
}


void keyPressed() {
  switch(key)
  {
  case '1':
    println("red");
    myColor = color(255, 0, 0);
    break;
  case '2':
    println("green");
    myColor = color(0, 255, 0);
    break;
  case '3':
    println("blue");
    myColor = color(0, 0, 255);
    break;
  case '4':
    println("yellow");
    myColor = color(255, 255, 0);
    break;
  case '5':
    println("black");
    myColor = color(0);
    break;
  default:
    println("wrong key");
    break;
  }
}