Hi Amal,
I have not had a chance to get the LED's working as you would like, but here is what I have so far. Please take a look at the VI's block diagram and see if you can play around with it as well. Since you are new to LabVIEW, please take a look at this short three hour tutorial that can help you get started with LabVIEW programming: http://zone.ni.com/devzone/cda/tut/p/id/5243.
The LED color can be changed using a property node. Take a look at both the program and the tutorial, and let me know if you need more assistance.
Have a great day, and best of luck on your application!!
Regards,
Ching P.
DAQ and Academic Hardware R&D
National Instruments
