In SAP Fiori Launchpad user can personalize it and select their theme of choice as well.
This blog discusses the way to find all the users who has adapted the page layout e.g. adding tiles to user home group or managing tiles for other groups that allow user personalization.
If you are trying to find users with personalized theme pleaseClick Here
System Details (On-Prem)
Below is the specification of the system used for this analysis.
NW AS ABAP
SAP FIORI FRONT-END SERVER
Method: Using Configuration Data for User – Table
SAP table WDY_CONF_USER (Web Dynpro: Configuration Data for User) is used to find the desired results.
1. Selection Parameters
User Scope (USER_ID)
Configuration Type (CONFIG_TYPE)
/UI2/ADAPTATION_PAGE(Component for Page Personalization)
2. Result Set
Result set may contain multiple entries for the user, one entry per user and per personaized group in launchpad