public static void evolve(Sprite s){
        if(!(s instanceof Prey)) return;
        if(s instanceof RedPrey && red < 3) red++;
        else if(s instanceof GreenPrey && green < 3) green++;
        else if(s instanceof BluePrey && blue < 3) blue++;
        Player.color = new Color(BASE_COLOR_AMOUNT + 30 * red,
                BASE_COLOR_AMOUNT + 30 * green,
                BASE_COLOR_AMOUNT + 30 * blue);
    }