Hi Praveen,
Please revise the tutorial for the ACT Connection. Within the mentioned document, it should clearly mention that, if SpaceClaim is your default geometry editor you beforehand have to open SpaceClaim and under options unselect the option "Use SpaceClaim Color Tones".
Once this little procedure is completed, you can create and start the ACT procedure.
Also, as mentioned within the tutorial, if SpaceClaim is your default geometry editor, please do not forget to assign a color to your BREp geometries. This will serve as named selection/s assigned to your domains.
Cheers
Ceyhan