Flutter : SurfaceTintColor

There are some new features on flutter material3 themes. One you can notice very quickly is the app bar color. Before, the app bar was filled with primary color, but with material3, the fill color is same as the background color.

There's another feature followed by material3 which you can see above. When the scroll contents are overlaping with the pinned app bar, the app bar's color slightly changes.

This feature was something that I didn't expect. I thought this is somekind of splash effect from CustomScrollView or something. But it was a property of the app bar called 'SurfaceTintColor'.
Setting it to Colors.transparent removed app bar color tint when app bar is over the scroll content.