The ability to customize the WordPress Login Form is included in WishList Member 3.1 and higher. This can be found in the Advanced Options > Logins > Styling section of WishList Member.
Options like removing the WordPress logo, changing the background color, adding an image, etc. are available.
A number of Templates are included and can be used to quickly and easily customize the WordPress Login Form.
Below is an example of a WordPress Login Form that has been customized using one of the available Templates.
There is also a Custom CSS option for those who like to work directly with the CSS code.
Note: You can view the WordPress Login Form for a site by adding /wp-login.php to the end of a site URL.
The video below provides additional details on customizing the WordPress Login Form: