One of the new features of APEX 5.1 is the introduction of APEX_THEME API which enables you to change the application theme style by user.

A very nice APEX 5.0 feature is to allow users to change the theme style using the APEX_UTIL.SET_CURRENT_THEME_STYLE procedure (deprecated in 5.1) but this change is only applied at application level. Therefore if one user changes the theme style, then it will be changed for all users.

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