I assume that you are using Word 2007 (Word version 12).

You can do this to some extent if you have cascading styles. How styles in Microsoft Word cascade by Shauna Kelly

You can also do it using Themes.

Both of these require that you set your styles in advance to take advantage of these methods. It is worth the time to do if you are going to be doing it often or might want to change your mind. Understanding Styles in Microsoft Word

For instance, all of my heading styles are based on the Heading 1 style which is based on no style. Heading 2 is based on Heading 1. Heading 3 is based on Heading 2. Heading 4 is based on Heading 3. I also have a Heading 2A based on Heading 2. If I change the font in Heading 1, it changes for all of the Heading styles. I have a style Body Text which is based on no style. I have 15 variations of body text with different indents or tabs, different line spacing and so forth. They are all based on either Body Text or one of it's derivatives. When I change the font in the Body Text style, all of the derivatives change. Those are cascading styles. Themes also deal with colors.