Click on "Profile" or "User Control Panel" in the top right of the screen.
Then click on the "Board Preferences" tab.
Under the global settings where it says my board style, click on the dropdown box and select a new style.
Click on the submit button.
Thats all!
Find the board style that you want to use by trying different themes.
This website is very customizable and will be suited to meet your needs.
Enjoy the website.