You can white-label your domain/sub-domain and customize your website as per the themes available.
You can learn how to white-label your website from the link mentioned below:
http://help.msg91.com/article/95-white-label-how-to-point-a-record-for-the-domain-or-sub-domain
Also, you can learn to customize your website with the help of the below-mentioned article:
http://help.msg91.com/article/96-how-to-design-website-for-selling-sms
For a video tutorial refer the link: https://www.youtube.com/watch?v=EPrDYCyBX0g