Hi Madhu,
You can assign SAP_CORBU Theme for ESS/MSS users to achieve the same look & feel.
Please follow the below steps:
Create a portal desktop using Portal Desktop Editor in the SAP Portal and assign it to the
ESS/MSS users using display rules. Activate the CORBU theme for the portal desktop.
For information on how to Create and Edit a Portal Desktop, please refer the following link: http://help.sap.com/saphelp_nw73/helpdata/en/48/1d5b9d71364269e10000000a421937/content.htm
and for information on Portal Display Rules, please refer the following link:
http://help.sap.com/saphelp_nw73/helpdata/en/48/1d5cfe71364269e10000000a421937/frameset.htm
Hope, this is helpful!!!
Regards,
Anurag