@Tomek , sorry for the typo. thank you for your response. I followed your advise and found one file matching with the description and deleted it, did log out and login. I see some apps pinned to taskbar have been removed. but the core issue still remains. That is the user name display foreground color and GNOME/GTK color themes are little ugly. However for other 3 uses on the machine, it is fine.
Regards
Ganesh