How to change your desktop theme in Linux?
Please click on the lower left corner icon (i.e. start button), the main menu select system Settings from the system will pop up a window in which to choose work space appearance icon, click on it, will display the following window:

In the column on the left click on the desktop theme, the theme of choice in the list you like, such as Steel, finally click on application, can be effective.

In the column on the left click on the desktop theme, the theme of choice in the list you like, such as Steel, finally click on application, can be effective.