Google Sites offers some basic formatting options. What if you want your Google Site to not look like a Google Site? The answer: CSS. We like headings in a site to draw attention to different sections of content. The most commonly used formatting option are Heading tags: <H1>, <H2>, etc. Use these and you'll get something like this:
What if you want some color or something more stylized? Then you'll need to get a little nerdy and edit the HTML. We can use some basic CSS styles to spruce up our site. In this case I'm using inline CSS on <div> tags to get what I want.
Now you have a nice bar for each heading. Change the background-color attribute to change the style a bit. Notice the border-radius attribute which makes it all a little less boxy. Without this our ends would be squared off.
Bob's your uncle! Now you have some style that makes your site not look like a Google Site.