We have spoken before about the need for diversity on the board. I have suggested previously that what you need to do is look at your stakeholders and make sure that the board is as diverse as your stakeholder. This has been discussed for some time.
However, how about the committees? How diverse do your committees need to be? If you have a nominating committee then this is a group that should be quite diverse so that they know lots of people, which will help with the diversity of the entire board. Your fundraising committee is another example of a group where knowing lots of different people will help.
If you have good board diversity you should be able to get good committee diversity easily if your committees are all made up of board members. If you have committee members who are not board members, which I recommend, then care should be taken to ensure diversity on the committee as well.