FractalTree2.java

public class FractalTree2 {
//black 0, 0, 0) and white(255, 255, 255)
  public static void main(String[] args) {
    Turtle t = new Turtle();
    t.delay(1);
    t.left(90);
    tree(t, 150, 10);
  }

  public static void tree(Turtle t, double size, int level) {
    int red = 255 - Math.min(20 * level, 255);  //take smaller of the two so that number will never exceed 255, puts cap on
    //as level increases, amt of red decreases
    //more red at low levels (level 0 is leaves, level 10 is stem) bc work backward
    int green = 0;
    int blue = 0;
    t.color(red, green, blue);
    if (level == 0) {
        t.forward(size);
        t.penup();
        t.backward(size);
        t.pendown();
    } else {
        // stem
        t.forward(size);
        // first branch
        t.left(30);
        tree(t, size * 0.8, level - 1);
        // second branch
        t.right(30 + 45);
        tree(t, size * 0.6, level - 1);
        t.left(45);
        t.penup();
        t.backward(size);
        t.pendown();        
    }
  }
}