Firefox themes are the add-ons (or extensions) that are available for users to customize the look and feel of their Firefox browsers. It is relatively easy to download and manage these themes so that you can switch up your browser look as often as you’d like.
In order to get these free themes you’ll need to go to https://addons.mozilla.org and select the themes section. Once there you will be able to download all the free themes you could ever want.
You can also get there by selecting Tools, followed by Add-Ons in the Firefox menu bar that is at the top of your screen when Firefox is opened. Once in Add-Ons you’ll want to select Themes and from there you can select the Get Themes link on the lower right hand side of that window.
Once you download themes they will appear in that same section found under the above section of the Firefox toolbar. There you will be able to preview, update, and select from the themes that you have downloaded previously. When selecting a theme to set as the default you can select ‘Use Theme’ under the applicable theme.
You’ll then be promoted to restart Firefox in order for the changes to take effect. Note that you only have to restart Firefox, not your computer. Upon relaunching Firefox you’ll see your new theme displayed in all it’s glory. Some themes do have preference options which you can access if available next to the ‘Use Theme’ button for the applicable theme.
Removing themes is easy as well by going into the same toolbar section once again. You’ll be able to select a new theme and also delete unused themes. For purposes of getting and managing Firefox themes in Mac OS X, it should be known that there is generally no need to mount or eject downloaded programs, nor is there a need to manually move the theme files to a certain folder; it is all done within Firefox. Also for many of the Extensions the same method of selecting and managing can be applied to those add-ons that are under Extensions and are not Themes.