Hi Mayank,
You can give a try this.
Within the screen you are calling give keyword
Leave to list processing
and then you can give whatever colors which are there in SAP
For making the text bold you can set Format intensified on or off depending on your requirement.
For more details you can refer to programs
program1 : demo_leave_to_list_processing
program2: demo_call_screen_from_list
Regards,
Sandeep Katoch