The possibilities to change an Element or Page is usually limited for an end user but you can change size and color for an Element or Page. See Personalizing Lobby Pages.
There are also tools for creating Elements (Element Designer), creating Data Sources that retrieve data from IFS Applications (Data Source Designer) and creating Lobby Pages (Page Designer).
To created and change Elements, Data Sources and Lobby pages you need the Lobby Designers package. Read more in the Technical documentation under IFS Administration & Configuration Guide/User Interface/Lobby.