They don’t make it that easy for you to see all SharePoint 2010 color themes at once, so here they are. I’ve taken the screenshots of the different theme settings and each default color. I’ve left the font as the default Verdana.
You can change the them at Site Actions-Site Settings-Site Theme under the Look and Feel section of SharePoint 2010.
This will save 30 minutes of your life that you will never get back.
Default (No Theme)