The themes are included inside the Gmail website. They are for making the webpage more interesting. A person can select the theme which interests him/her.
You can make your Gmail background different by applying themes. These themes have interesting backgrounds in it. You can also upload a manual background.
There are no other ways ways of including new themes to gmail but this wonderful post on dynamic Gmail themes which change pictures and looks with time of the day or hourly have a great thing for improving appearance.. http://sameerkhansblog.blogspot.com/2009/01/gmail-themes-dynamic-pictures-google.html
Gmail has various themes present in it. The theme helps to build the person his account as he wants to. The themes are present in the settings tab.
Themes are pre-loaded into the Gmail account. You can apply them whenever you want. It is present in the settings in the top right corner.
Black is one of the theme of Gmail inbuilt. You can change your Gmail to black anytime you want. In the settings, there is themes where you can select it.
Pick a ThemeSettingsThemes
The backgrund of Gmail can be changed by themes. There are various custom themes available. Blue, black, green, planets, grass etc are some examples.
On Gmail, I know you can make one or use the themes they have to offer. Gmail is very good.
Choose settings and then Themes.
You can decorate your profile on Gmail. You can add themes to your account. A Custom wallpaper could also be added.
You can decorate your Gmail inbox by applying themes. On the right, above the mails there is settings. You can click that and apply settings.
You can put a background on a gmail page via various themes. There are themes like black, green, blue, white etc. They put their respective backgrounds on the screen.