You can select a theme from white and black and can customize. You can add your own background. It can be from a URL, picassa or anywhere in your drives.
There is no orange clock in Gmail. It might be a theme which is present in the Gmail. You can make it to default theme.
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.
Unfortunately you cannot change your theme on Gmail on ipad.
You cannot add your logo to Gmail account. You can personalize by adding your theme. Adding icon or logo to Gmail is not possible.
You cannot create custom theme for anything. However you could change some of the properties. Like you could set a custom background image.
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.
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.
You have to attain a minimum age to make a Gmail. The age of creation of Gmail is 13 years. You can easily create a account after that.
On Gmail you can make a little face that you prefer. Gmail supports a number of emoticons which are used to express different feelings.
You can make a Gmail account for yourself easily. You just have to register using the Gmail information. You have to also agree to the terms and conditions.
You cannot make audio call on Gmail. However video calls are possible in Hangouts. It is the latest IM of Gmail service.
You can add photos to your Gmail profile background easily. The background can be changed in the themes bar. You can select the theme that interests you.