I have the Yellow button mapped to Videos in the Remote Shortcuts section of my Android Clients. It seems to have a bug, in that it behaves differently depending on where you are in the system.
If you are in Live TV when you press Yellow it takes you to wherever section you were last in the menu (Guide/TV Shows/Schedule etc ) if you then press Yellow again it takes you correctly to the Videos tab.
So it works correctly from anywhere in the system except Live TV when it works as a backup button.
I've tested this with the API navigate call too and it is the same behaviour.
I'm running the latest beta (3.20.1014)