NSMutableAttributedString* attrStr = [NSMutableAttributedString attributedStringWithString:@"Hello World!"];

[attrStr setFont:[UIFont systemFontOfSize:12]];

[attrStr setTextColor:[UIColor grayColor]];

[attrStr setTextColor:[UIColor redColor] range:NSMakeRange(0,5)];

myAttributedLabel.attributedText = attrStr;

myAttributedLabel.textAlignment = UITextAlignmentJustify;

NSMutableAttributedString Example