As you can see in the two image provided, light grey looks greenish despite reading a value of #F6F6F6 , then it looks normal after changing the scaffold background to White.

Are Flutter Widgets transparent by default ?!
Why changing the color of the Scaffold background seems to have an effect on widget color?
Is it a bug in Flutter ?

Take note this color bug is the same in physical device as in the emulator.

The code changed between two images

ThemeData(
   scaffoldBackgroundColor: Colors.white,
);