Hi,
The code given by Rajkumar is the correct way.
Try with this.
1.Maintain a 4 char length field in output internal table(Having data to display).
2.Set the value for the additional color field as 'C310' against the required row in internal table.
eg. In o/p internal table
FIELD1 FIELD2 COLOR
aaaaa 10
subtotal 10 C310
3.In ALV layout, set layout-info_fieldname = 'COLOR'. "The color field name
4.Pass layout,field catlog and output internal table while calling ALV.
Regards
Sreeknath