WordPress.com offers two different options
A. If you don’t purchase the CSS upgrade, you can alter the appearance of your theme only through the use of customized headers and sidebar widgets.
- You can choose a theme from the admin area of your blog -> Appearance -> Themes
- Many provide for a customized header and most have sidebar widgets to allow for posting of unique images, etc. with which to personalize your blog.
B. You can edit your css style sheet or create one of your own only if you purchase an upgrade and undertake css customization yourself. However, you cannot edit the underlying html or php in the theme template.
- If you do not wish to use one of the themes made available at wordpress.com through your admin section -> Appearance -> Themes then you can choose to undertake css customizing a wordpress.com theme or make your own, or you can move to self hosting or a web host and altering an available theme.
- CSS customization can be used to improve on any existing theme; you can define your own classes for use in posts; you can select the Sandbox theme and build on one of the Minimalist layouts or, opt for no stylesheet and do it all yourself. If you feel you are up to the challenge of customizing a theme then these entries: Custom CSS , Custom CSS Improvement and Discount, Editing CSS will be helpful.
- Although there is a CSS forum and other bloggers may volunteer to help you if needs be, and there are also css resources that you can access, it’s important to understand that there is no staff support for css customization.
- The 15$ you pay to upgrade a wordpress.com blog enables you to to alter the appearance of your theme and but not the underlying php code. Purchasing the upgrade entitles you to customize css on one blog for one year.
WordPress.org offers free software to self-hosting bloggers
Although some themes at wordpress.com and at wordpress.org may appear to be the same they are not; the software is different. Check here for an outline of the differences between wordpress.com and wordpress.org. You can also confirm this by consulting the wordpress.com Support Documentation.