Label文字多種顏色

NSMutableAttributedString *str = [[NSMutableAttributedString alloc] initWithString:[NSString stringWithFormat:@"總共%@題",numStr]];
      [str addAttribute:NSForegroundColorAttributeName value:DOMINICAL_COLOR range:NSMakeRange(0,2)];
      [str addAttribute:NSForegroundColorAttributeName value:SHALLOW_GREEN_COLOR range:NSMakeRange(2,numStr.length)];
      [str addAttribute:NSForegroundColorAttributeName value:DOMINICAL_COLOR range:NSMakeRange(2+numStr.length,1)];
      
      UILabel *titleLabel3 = [[UILabel alloc] initWithFrame:CGRectMake(5, CGRectGetMaxY(lineView.frame)+5, 100, 20)];
      titleLabel3.backgroundColor = [UIColor clearColor];
      titleLabel3.font = MBLACK15_FONT;
      titleLabel3.attributedText = str;
      [self addSubview:titleLabel3];