I have copper ice maker kit to connect. My coldwater suply goes from galvonized pipe to the flexable silver tubing, Can I connect the self piercing compression fitting onto the flexable silver tubing?

No, if you connect it to anything, connect it to the galvanized line -- Even better, if it's an option, install a double outlet stop under the kitchen sink and run a 1/4 inch soft copper line from the kitchen sink cabinet base through the floor joists to the refrigerator location.

If the flexible silver tubing is 3/8's copper tubbing and the saddle is made for 3/8's then yes you can do it the way you said. If your silver pipe is a braided material then do not use the saddle because inside of the braid is a rubber tube and it will not seal.