GtkSwitch background isn't logical

[Francesco Ferraro]

Step to reproduce the bug:
     - Open a GTK3 program with Ambiance or Radiance theme (e.g: Gnome Tweak Tool)
     - Find a "Switchbutton" (see "Switchbuttons.png")
     - Click on it and see the background canging from Orange (ON) to Light Brown (OFF)
     - Drag slowly the switchbutton and see both ON and OFF position with Orange or Light Brown (see "Switchbuttons_real.png")

Expected behaviour:
     - Dragging a switchbutton should reveal Orange background color under ON position and Light Brown under OFF position (see "Switchbuttons_expected.png")

For further information see images related

[Adolfo Jayme Barrientos (fitojb)]

This is not light-themes fault. You can see this behavior as well in other themes, such as Adwaita.

[Lars Karlitski (larsu)]

Interesting. I've always thought of the whole widget lighting up when it is turned to ON, because the frame is drawn in the active color as well.