Game Boy Color Button Silicone - Clear
Have been waiting on these to be available for a long time and they are finally here.
The Game Boy Color Silicone membranes
Now i would strongly suggest that if you want the "Original" feel of the action buttons (A & B also the Dpad) is to use original silicone's and just use these coloured Start/Select buttons. This is fine to do in a solid colour shell
If your build is a transparent one then you have a choose between "original" feel buttons or the coloured look.