Why does Android button shape changes but not color after applying background drawable (Android, button, Android drawable, development)?

Yes, that's because the Material Design Theme has been applied to your app.
So how do you get of this?

I guess we have two ways to solve this, either you change the material theme or change the button.
Let's see one by one.

• Theme changing

Change the theme from Material to AppCompat theme.

TO

• Change the default view. Like this,

2. android:layout_width="wrap_content" android:layout_height="wrap_content"  
3. android:text="Option A"/> 

To

2. android:layout_width="wrap_content" android:layout_height="wrap_content"  
3. android:text="Option A"/> 

So yeah that's it. Hope now you got the colors back. Learn More.