Fragment has default white background on replace() instead of transparent one

you can use the following property for all your root layouts, views, fragments, containers etc:

android:background="@android:color/transparent"

If you want to display the background of your activity only then all the views should be transparent.

For this you have to set android:background="@android:color/transparent" for each view other than the MainActivity's backgroud. i.e background for

• the Fragments
• their child Views
• the ListView(s)
• and ListView's items / childs etc.

In short each view must have a transparent background so that the Activities' background is not overlapped and visible to the user.