How to paint silicone rubber parts except silk printing method ?
It is usually a bad idea to paint silicone. The better option is casting the silicone in the color you need.
If painting must occur for additional details, then you might consider airbrushing as shown in this video by Smooth-On:
Maybe you could contact engineering support at the company in your link? According to your link, it sounds like the trick to painted silicone of an acceptable lifespan is in the clear coating over the paint.
Actually its not bad idea but im wondering how to find the correct paint for silicone rubber ?