UILabel *Label = [[UILabel alloc] initWithFrame:CGRectMake(20, 300, 300, 30)];
NSMutableAttributedString *string = [[NSMutableAttributedString alloc] initWithString:@"set background color with button"];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor blueColor] range:NSMakeRange(0,2)];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(6,12)];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor greenColor] range:NSMakeRange(19,6)];
[string addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"Arial-BoldItalicMT" size:17.0] range:NSMakeRange(0, 5)];
[string addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"HelveticaNeue-Bold" size:17.0] range:NSMakeRange(6, 12)];
[string addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"Courier-BoldOblique" size:17.0] range:NSMakeRange(19, 6)];
Label.attributedText = string;
[self.view addSubview:Label];